Env-Wr 100-800 Water Reso

CHAPTER Env-Wr 100 ORGANIZATIONAL RULES

PART Env-Wr 101 DEFINITIONS

REVISION NOTE:

Document #13979, effective 5-24-24, readopted with amendment Chapter Env-Wr 100 and Chapter Env-Wr 200. Document #13979 inserted the following new definitions in Part Env-Wr 101: Env-Wr 101.01 (“1,000-year design event”), Env-Wr 101.04 (“250% of the 100-year design event”), Env-Wr 101.06 (“campsite”), Env-Wr 101.13 (“drainage area”), Env-Wr 101.16 (“engineer”), Env-Wr 101.17 (“exempt dam”), Env-Wr 101.26 (“manual operations”), Env-Wr 101.27 (“maximum discharge capacity”), Env-Wr 101.28 (“maximum pool level”), Env-Wr 101.29 (“maximum storage capacity”), Env-Wr 101.34 (“normal pool”), Env-Wr 101.36 (“overtopping”), Env-Wr 101.41 (“regulatory discharge capacity”), and Env-Wr 101.48 (“top of dam”).

Document #13979 deleted the following definitions: Env-Wr 101.04 (“applicant”), Env-Wr 101.05 (“breached dam”), Env-Wr 101.07 (“construction engineer”), Env-Wr 101.13 )”discharge capacity”), Env-Wr 101.24 (“low economic loss”), Env-Wr 101.37 (“reversible environmental losses”), Env-Wr 101.40 (“specifications”), Env-Wr 101.42 (“storage capacity”), Env-Wr 101.43 (“stream”), and Env-Wr 101.45 (“wave run up). Document #13979 also deleted Part Env-Wr 102 titled “Duties of the Department” and Part Env-Wr 103 titled “Access to Files.”

Document #13979 replaces all prior filings affecting the rules in the former Chapter Env-Wr 100 and former Chapter Env-Wr 200. Due to the changes made by #13979, the existing rules in Part Env-Wr 101 were extensively renumbered as indicated in the source notes.

The prior filings affecting the deleted rules in Part Env-Wr 101 included the following documents:

Env-Wr 101.04 and Env-Wr 101.05

#1716, eff 2-20-81

#2207, eff 12-13-82

#2900, eff 11-7-84;

#4491, eff 9-20-88

#5080, eff 2-22-91

#6462-A, eff 2-21-97

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-14

Env-Wr 101.07 and Env-Wr 101.13

#1716, eff 2-20-81

#2207, eff 12-13-82

#2900, eff 11-7-84;

#5080, eff 2-22-91

#6462-A, eff 2-21-97

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-14

Env-Wr 101.24

#4278, eff 6-30-87

#5080, eff 2-22-91

#6462-A, eff 2-21-97

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-1

Env-Wr 101.37, Env-Wr 101.40, Env-Wr 101.42, and Env-Wr 101.43

#5080, eff 2-22-91

#6462-A, eff 2-21-97

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-14

Env-Wr 101.45

#10508, eff 1-22-14

The prior filings affecting the deleted rule Env-Wr 102.01 titled “Summary of Duties” in Part Env-Wr 102 included the following documents:

#1716, eff 2-20-81

#2207, eff 12-13-82

#2900, eff 11-7-84, EXPIRED 11-7-90

#5080, eff 2-22-91

#6462-A, eff 2-21-97

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-14

The prior filings affecting the deleted rule Env-Wr 103.01 titled “Public Records: Access to Files” in Part Env-Wr 103 included the following documents:

#1716, eff 2-20-81

#2207, eff 12-13-82

#2900, eff 11-7-84

#4278, eff 6-30-87

#4580, eff 2-27-89

#5080, eff 2-22-91

#6462-A, eff 2-21-97 (formerly Env-Wr 105.01)

#8288, INTERIM, eff 2-21-05

#8412, eff 8-20-05

#10508, eff 1-22-14

As organizational and practice and procedure rules, the rules in Document #13979 will not expire except pursuant to RSA 541-A:17, II.

PART Env-Wr 101 DEFINITIONS

Env-Wr 101.01 “1,000-year design event” means the flood event calculated using the 24-hour rainfall that has a 0.1 percent chance of being equaled or exceeded in a period of one year.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.02 “100-year design event” means the flood event calculated using the 24-hour rainfall that has a one percent chance of being equaled or exceeded in a period of one year.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.01) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.03 “50-year design event” means the flood event calculated using the 24-hour rainfall that has a 2 percent chance of being equaled or exceeded in a period of one year.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by 8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.02) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.04 “250% of the 100-year design event” means the flood event equal to 2.5 times the 100-year design event inflow hydrograph applied directly upstream of the subject impoundment.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.05 “Acre-foot” means the volume of water that would cover one acre to a depth of one foot, or 43,560 cubic feet.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4491, eff 9-20-88; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.03) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.06 “Campsite” means "campsite" as defined in RSA 216-I:1, II, namely "a parcel of land in a recreational campground or camping park rented for the placement of a tent, recreational vehicle, or a recreational camping cabin for the overnight use of its occupants."

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.07 “Classification of a dam” means “classification of a dam” as defined in RSA 482:2, I, namely, "the potential hazard classification placed on a dam by the department based on the potential threat to life and the potential extent of property damage in the event of accidental damage to, or failure of, the dam structure. The classifications shall be "non-menace," "low hazard potential," "significant hazard potential," or "high hazard potential" defined as follows:

(a) “Non-menace structure” means a dam that is not a menace because it is in a location and of a size that failure or misoperation of the dam would not result in probable loss of life or loss to property, or it is located on a great pond with a maximum height of less than 6 feet;

(b) “Low hazard structure” means a dam that has a low hazard potential because it is in a location and of a size that failure or misoperation of the dam would result in any of the following or meets other parameters set-forth below:

(1) Overtopping of any road, excepting unmaintained class VI roads and recreational trails or crossings, accessing property other than the dam owner’s which could render the road impassable or otherwise interrupt public safety services, is classified at a minimum as a “low hazard structure”;

(2) A dam that is 6 feet in height or greater and stores a maximum volume of 50 acre-feet or greater, or that is 25 feet in height or greater and stores a maximum volume of 15 acre-feet or greater, is classified at a minimum as a “low hazard structure”;

(3) A dam that creates a surface impoundment for liquid industrial or liquid commercial wastes, septage, or sewage, or that is known to impound contaminated sediment, regardless of height or storage capacity, is classified at a minimum as a “low hazard structure”;

(4) Any flooding to a developed structure on a property other than the dam owner’s that is not normally occupied; or

(5) Any dam that is part of or integral to a local or private roadway accessing property other than the dam owner’s is classified at a minimum as a “low hazard structure”.

(c) “Significant hazard structure” means a dam that has a significant hazard potential because it is in a location and of a size that failure or misoperation of the dam would result in any of the following or meets other parameters set-forth below:

(1) Flooding between the lowest contact of the foundation with the ground surface and up to one foot above the lowest finished floor elevation of a normally occupied residential, commercial, or industrial structure;

(2) Up to one foot of flooding above ground surface at any point under or immediately adjacent to a normally occupied ground supported residential, commercial, or industrial structure;

(3) One foot or more of overtopping to a class I or II route located downstream of the dam which could render the road impassable or otherwise interrupt public safety services; or

(4) Any dam that is part of or integral to a class I or II route is classified at a minimum, as a “significant hazard structure”.

(d) “High hazard structure” means a dam that has a high hazard potential because it is in a location and of a size that failure or misoperation of the dam would result in probable loss of human life or meets other parameters set-forth below:

(1) One foot or more of flooding above the lowest finished floor elevation of a normally occupied residential, commercial, or industrial structure;

(2) One foot or more of flooding above ground surface at any point under or immediately adjacent to a normally occupied ground supported residential, commercial, or industrial structure;

(3) Failure of a structurally attached, normally occupied habitable residential, commercial, or industrial structure;

(4) Campsites receiving any level of flooding due to a dam failure; or

(5) Any other circumstance which would more likely than not cause one or more deaths.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.06) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.08 “Controlled breach” means an opening in a dam that extends from the top of the dam to the streambed made specifically for the purpose of lowering the level of impounded water to a safe level for the dam.

Source. #1702, eff 1-1-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.09 “Dam” means “dam” as defined in RSA 482:2, II, as reprinted in Appendix C.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.10 “Dam in disrepair” means “dam in disrepair” as defined by RSA 482:2, V, as reprinted in Appendix C.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.11 “Days” means calendar days unless otherwise specified.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.12 “Department” means the New Hampshire department of environmental services.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.13 “Drainage area” means the total surface area upstream of a point on a stream or dam where all flowing surface water converges.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.14 “Emergency action plan” means “emergency action plan” as defined in RSA 482:2, VI, as reprinted in Appendix C.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24

Env-Wr 101.15 “Emergency condition” means a situation exists at a dam which jeopardizes its ability to control or impound water or contents.

Env-Wr 101.16 “Engineer” means a professional engineer registered and licensed in New Hampshire.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.17 “Exempt dam” means a dam that meets either of the following:

(a) A previously permitted dam that no longer meets the definition of a “dam” as defined in RSA 482:2, II; or

(b) A non-permitted existing dam that does not meet the definition of a “dam” as defined in RSA 482:2, II.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.18 “Flashboards” means boards which raise the pond elevation above the permanent spillway crest and are designed to automatically yield, activate, or trip when the water level rises to a particular level.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.17) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.19 “Freeboard” means the vertical distance from the water surface to the lowest elevation at which water would flow over the dam at a section not designed for overtopping.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.18) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.20 “Great pond” means a water body of 10 acres or more in its natural condition.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4278, eff 6-30-87; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.19) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.21 “Height” means the vertical distance from the lowest point of undisturbed natural ground on the downstream side of the dam to the highest part of the dam which could impound water.

Source. #4278, eff 6-30-87; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.20) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.22 “High hazard structure” means a dam as defined in Env-Wr 101.07(d).

Source. #4278, eff 6-30-87; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.21) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.23 “Inflow design flood” is the flood flow above which the incremental increase in water surface elevation downstream of the dam due to failure is no longer considered to present an unacceptable additional downstream threat.

Source. #4278, eff 6-30-87; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.22) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.24 “Inland public water” as used in RSA 482:79 means any public water of 10 acres or more whose level is controlled by a dam.

Source. #4278, eff 6-30-87; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.23) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.25 “Low hazard structure” means a dam as defined in Env-Wr 101.07(b).

Env-Wr 101.26 “Manual operations” means activation or manipulation of gates, valves, stoplogs, flashboards, turbines, or other outlet works by means by human intervention.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.27 “Maximum discharge capacity” means the discharge capacity of a dam at maximum pool level without the benefit of manual operations.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.28 “Maximum pool level” means the water surface elevation of the impoundment at which overtopping is expected to occur.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.29 “Maximum storage capacity” means the volume of water and liquid contents which could be impounded by a dam when the water level is at the maximum pool level.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.30 “Menace to public safety” as used in RSA 482:2, V and “menace to the public safety” as used in RSA 482:9, III, means that the failure or misoperation of the dam would threaten human life or interrupt safety services. The term applies to any low hazard, significant hazard, or high hazard dam but not to any non-menace structure.

Source. #4278, eff 6-30-87; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.26) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.31 “Mills” means “mills” as defined by RSA 482:2, VII, as reprinted in Appendix C.

Source. #4399, eff 4-19-88, EXPIRED 4-19-90

New. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.27) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.32 “Non-menace structure” means a dam as defined in Env-Wr 101.07(a).

Source. #4491, eff 9-20-88; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.28) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.33 “Non-permitted dam” means a dam for which a permit, order, or authorization for construction or registration has never been issued by the department or a predecessor state agency responsible for such at the time.

Source. #4491, eff 9-20-88; ss by #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.29) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.34 “Normal pool” means the water surface level of an impoundment when the water level is at the elevation of the primary outlet structure or spillway.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.35 “Normal storage capacity” means the volume of water and liquid contents which is impounded, when the water level is at the elevation of the primary outlet structure or spillway.

Env-Wr 101.36 “Overtopping” means flow over the top of the dam onto areas not specifically designed for flow when the maximum pool level is exceeded.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.37 “Owner” means the person, persons or entity who legally owns a dam or associated flowage rights, if any, or who possesses or exercises legal rights or obligations to operate, maintain, repair, or reconstruct a dam.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.31) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.38 “Person” means “person” as defined by RSA 482:2, VIII, as reprinted in Appendix C.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.32) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.39 “Plans” means engineering drawings including plan views, elevations, sections, details, specifications, or other documents related to the design, construction, or reconstruction of a dam.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.33) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.40 “Reconstruction” means “reconstruction” as defined by RSA 482:2, X, as reprinted in Appendix C.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.34) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.41 “Regulatory discharge capacity” means the discharge capacity of a dam when the water is one foot below maximum pool level without the benefit of manual operations.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

Env-Wr 101.42 “Removal” means the physical elimination of a dam as an impounding structure as governed by Env-Wr 600.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.35) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.43 “Repair” means any physical alteration of or modification to a dam that does not meet the definition of reconstruction as defined by RSA 482:2, X.

Source. #5080, eff 2-22-91; ss by #6462-A, eff 2-21-97; ss by #8288, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8412, eff 8-20-05; ss by #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.36) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.44 “Ruins” means the remains of a dam which no longer impounds water and whose deterioration is to the extent that the original configuration can no longer be determined.

Source. #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.38) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.45 “Significant hazard structure” means a dam as defined in Env-Wr 101.07(c).

Source. #10508, eff 1-22-14; ss by #13979, eff 5-24-24 (formerly Env-Wr 101.39) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.46 “Stage” means the depth of water or elevation of water surface in relation to a specific point at or near the dam.

Source. #13979, eff 5-24-24 (formerly Env-Wr 101.41) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.47 “Sunny day flow” means the flow occurring in a river or stream channel during normal non-storm event hydrologic conditions.

Source. #13979, eff 5-24-24 (formerly Env-Wr 101.44) (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 101.48 “Top of the dam” means the lowest elevation of the dam crest, above which overtopping of the dam is expected to occur.

Source. (See Revision Note at chapter heading for Env-Wr 100) #13979, eff 5-24-24

CHAPTER Env-Wr 200 PROCEDURES

PART Env-Wr 201 PURPOSE AND APPLICABILITY

Env-Wr 201.01 Purpose.

(a) The rules in this chapter are intended to supplement Env-C 200 and RSA 541-A in governing proceedings before the department under RSA 482. These rules shall be construed to secure a just and speedy determination of every proceeding.

(b) The purpose of any proceeding governed by this chapter shall be to allow the department to acquire sufficient information to make a decision, and to afford persons who may be affected by decisions of the department the opportunity to present evidence and argument to the department prior to the making of that decision.

Source. #1644, eff 10-7-80; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 201.02 Applicability. These rules shall apply to all proceedings initiated under RSA 482 relative to dams and lake level determinations.

PART Env-Wr 202 WAIVERS

Env-Wr 202.01 Purpose. The purpose of these waiver rules is to accommodate situations in which strict compliance with all applicable requirements specified in subtitle Env-Wr might not be necessary or in the best interests of human life, public safety, or the environment.

Source. #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 202.02 Applicability. These waiver rules shall apply to any person who is or would be directly and adversely affected by the strict application of these rules who wishes to request a waiver of the rule(s) or portion(s) thereof which so affect that person.

Source. #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 202.03 Waiver Request.

(a) The person requesting the waiver(s) shall submit the request to the department in writing.

(b) If the waiver is needed in conjunction with an application filed under Env-Wr 400, the waiver request shall be submitted with the application or as soon thereafter as the need for the waiver is identified.

(1) A description of the dam to which the waiver request relates, including name, address, and state dam inventory number;

(2) A citation to the specific section(s) of the rules from which a waiver is sought;

(3) A complete explanation of why a waiver is being requested, including an explanation of the economic and operational consequences of complying with the rule;

(4) A complete explanation of any proposed alternative(s) to the rule(s) for which a waiver is sought, with appropriate supporting information;

(5) Whether the need for the waiver is temporary and, if so, the length of time the waiver is needed; and

(6) A complete explanation of how granting a waiver would be consistent with the criteria specified in Env-Wr 202.04(a).

(d) The person requesting the waiver(s) shall sign and date the request.

(e) The person’s signature shall constitute certification that:

(1) The information provided is true, complete, and not misleading to the knowledge and belief of the signer; and

(2) The signer understands that any waiver granted based on false, incomplete, or misleading information shall be subject to revocation.

Source. #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 202.04 Action on Waiver Request.

(a) Subject to (b), below, the department shall grant a waiver upon determining that:

(1) Granting a waiver will be consistent with the intent of RSA 482;

(2) Human life, public safety, and the environment will be protected; and

(3) Any benefit to the public or the environment from strict compliance with the rule is outweighed by the economic and operational consequences of strict compliance with the rule.

(b) No waiver shall be granted of a requirement that is prescribed by statute, unless a waiver is expressly allowed by the statute that would be waived.

(c) The department shall issue a written decision on a request for a waiver within 60 days of a submittal completed in accordance with Env-Wr 202.03. If the request is denied, the decision shall specify the reason(s) for the denial.

(d) If the need for the waiver is temporary, the department shall identify the expiration date of the waiver in its written decision.

(e) If the department determines that conditions are necessary for the criteria specified in (a), above, to be met, the department shall include such conditions as are necessary in the waiver.

Source. #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

PART Env-Wr 203 PROCEEDINGS

Env-Wr 203.01 Public Hearings. Any hearing held to receive public comment under the following statutory provisions shall be conducted in accordance with the provisions of Env-C 200 applicable to non-adjudicative hearings:

(a) RSA 482:6 relative to the management and control of the outlet of a great pond;

(b) RSA 482:9, V(a) relative to public benefit of a proposed significant hazard or high hazard dam;

(d) RSA 482:79 relative to lake level determinations.

Env-Wr 203.02 Permit Proceedings. The processing of an application for approval to construct or reconstruct a dam shall be a non-adjudicative proceeding in accordance with RSA 541-A:29, II(a).

Source. #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

PART Env-Wr 204 DECISION AND APPEALS

Env-Wr 204.01 Department Decisions.

(a) All final department decisions under RSA 482 shall be issued in writing.

(b) A final decision to grant a permit application shall be distributed as follows:

(1) Subject to Env-Wr 404.02(b), the original shall be sent to the applicant; and

(2) Copies shall be sent to all municipalities that were notified of the application pursuant to Env-Wr 304.03 or Env-Wr 402.07.

(1) The original shall be sent to the owner or designee applicant; and

(2) Copies shall be sent to all municipalities that were notified of the application pursuant to Env-Wr 304.03 or Env-Wr 402.07.

(d) Copies of a final decision in a lake level investigation shall be sent to:

(1) The owner of the dam that is the subject of the order;

(2) The person(s) who requested the investigation, if any;

(3) Each municipality in which the impounded water is located; and

(4) Each person who participated in the investigation who specifically requested to be notified of the decision.

(e) Copies of an order issued pursuant to RSA 482:11 or RSA 482:12 shall be sent to:

(1) The owner of the dam that is the subject of the order; and

(2) Each municipality in which the impounded water is located.

Source. #1644, eff 10-7-80; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4336, eff 11-5-87; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (from Env-Wr 205.01); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

Env-Wr 204.02 Appeals. Appeals of department decisions under RSA 482 shall be directed to the water council in accordance with RSA 21-O:14 and Ec-Wtr 200.

Source. #1644, eff 10-7-80; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (from Env-Wr 205.02); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8413, eff 8-20-05; ss by #10509, eff 1-22-14; ss by #13979, eff 5-24-24 (see Revision Note at chapter heading for Env-Wr 100)

CHAPTER Env-Wr 300 EXISTING DAMS

PART Env-Wr 301 PURPOSE AND APPLICABILITY

Env-Wr 301.01 Purpose. The purpose of this chapter is to ensure that existing dams are maintained in a manner so that public safety and the environment are protected.

Source. #4399, eff 4-19-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 301.02 Applicability. The requirements in this chapter shall apply to:

(a) Any structure which qualifies as a dam in accordance with RSA 482:2, II and that is not regulated by the Federal Energy Regulatory Commission; and

(b) Any roadway culvert that does not meet the parameters of Env-Wr 301.03.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4399, eff 4-19-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 301.03 Roadway Culverts.

(a) A roadway embankment whose culvert is placed along the natural bed elevation of the stream shall not be considered a dam if during the 25-year design event the water surface elevation at the culvert inlet is less than 6 feet above the water surface elevation at the culvert outlet.

(b) If additional culverts exist through the roadway embankment, their capacity(ies) may be used to determine the water surface elevation during the 25-year design event.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4399, eff 4-19-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 302 DAM INSPECTIONS; REPAIRS; ALTERNATIVES TO REPAIR

Env-Wr 302.01 Dam Inventory. The department shall maintain an inventory of all jurisdictional dams in the state as to ownership, height, location, and hazard classification.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff

8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 302.02 Dam Inspections.

(a) The department shall inspect dams in accordance with the following frequency:

(1) Low hazard structures shall be inspected at least once every 6 years;

(2) Significant hazard structures shall be inspected at least once every 4 years; and

(3) High hazard structures shall be inspected at least once every 2 years.

(b) An individual may request the department to inspect any dam by putting such request in writing to the department or provided by electronic mail to: damsafety@des.nh.gov.

(c) The department shall review the request and any other available information on the dam and shall schedule an inspection of the dam.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 302.03 Repairs Required.

(a) Subject to (c), below, if the department determines as a result of an inspection that repairs or reconstruction to a dam are needed to maintain the dam in a safe condition, it shall notify the owner in writing of such repairs or reconstruction as are necessary and request the owner to undertake such repairs within the time period specified in the notice.

(b) If the owner does not undertake the needed repairs or reconstruction within the time period indicated in a notice sent pursuant to (a), above, the department shall proceed under RSA 482:12 to order the owner to undertake the repairs or reconstruction.

(c) The department shall not issue a request but instead shall directly issue an order requiring repairs or reconstruction if:

(1) The condition of the dam poses an imminent threat to public safety; or

(2) The owner of the dam has been non-responsive to department requests relating to compliance issues.

Env-Wr 302.04 Alternatives to Repairing or Reconstructing a Dam.

(a) In lieu of repairing or reconstructing a dam as required pursuant to Env-Wr 302.03, the owner may:

(1) Remove the dam in accordance with chapter Env-Wr 600; or

(2) Modify the dam in accordance with Env-Wr 302.05.

(b) Such removal or modification shall be equivalent to complying with Env-Wr 302.03.

Env-Wr 302.05 Modifications to Remove a Dam From Jurisdiction.

(a) The owner may request approval from the department to modify the dam so it no longer meets the definition of a dam in accordance with RSA 482:2, II.

(b) To request approval for modification, the owner shall submit the following information in writing to the department:

(1) The name, mailing address, email address, and daytime telephone number of the owner;

(2) The date of the department’s order or request to repair, reconstruct, or remove the dam, if any, and if none, the:

a. Tax map and lot number of the property on which the dam is located;

b. A description of the specific location of the dam;

c. Name of the stream, river, or other water body on which the dam is located, if applicable;

d. Reason(s) for the proposed modification; and

e. Hazard classification of the dam;

(3) A detailed explanation of the specific work that will be performed, including anticipated inflows and outflows during the work and the effect of such flows on upstream and downstream property and any potential public safety concerns;

(4) The name(s), mailing address(es), email address(es), and daytime telephone number(s) of the person(s) proposed to perform the work; and

(5) A proposed schedule for the work, which shall include time for the notice and hearing required by RSA 482:13, as applicable.

(1) The proposed modification will cause the structure to no longer meet the definition of a dam; and

(2) The work will be performed in a manner that will not cause flows that would result in property damage or threaten public safety upstream or downstream of the dam.

(d) If the department determines that after the review of the proposed modification the structure will still meet the definition of a dam, the department shall require the submission of an application to reconstruct a dam and approval of the modification of the dam shall be given provided that:

(1) The work will be performed in a manner that will not cause property damage or threaten public safety upstream or downstream of the dam;

(2) The threat posed to life or property after completion of the work is no more than it would have been if the work required by the department pursuant to Env-Wr 302.03 had been completed, if applicable; and

(3) The requirements of Env-Wr 303.10 relative to discharge capacity will be met as a result of the proposed work.

Env-Wr 302.06 Notification to Public. After receiving approval pursuant to Env-Wr 302.03 through Env-Wr 302.05, the owner shall refrain from undertaking the work until the requirements of RSA 211:11 relative to notification to NH fish and game department, and RSA 482:13 relative to notice to municipalities have been met, as applicable.

Source. #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 303 REQUIREMENTS FOR EXISTING DAMS

Env-Wr 303.01 Annual Registration Fee.

(a) Pursuant to RSA 482:8-a, annual registration fees for dams in the amount specified in RSA 482:8-a shall be payable to the department by January 1 of each calendar year.

(b) The department shall send a written notice, by October 31 of each year, to each owner specifying the amount of the registration fee that shall be due.

(c) The department shall send a second notice to each owner who fails to submit the annual registration fee by January 1. Such notice shall inform the owner that the payment is overdue and that if the owner fails to submit the registration fee within 10 days, the owner shall be subject to the penalties authorized by RSA 482:89.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4534, eff 11-10-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 303.02 Review of Hazard Classification.

(a) The department shall review the classification of a dam in conjunction with any inspection conducted pursuant to Env-Wr 302.02.

(b) Classifications for all dams shall be determined by the impacts caused by modeling the failure occurring at the peak reservoir levels associated with sunny-day, 50-year and 100-year base flow conditions. The breach parameters used shall conform to Table 5.1 and Figure 5.1 as contained within Env-Wr 502.04.

(c) If the department determines that a dam no longer meets the criteria of the class to which it had been assigned, the department shall reassign the dam to the proper classification of a dam as defined in Env-Wr 101.07.

(d) If reassigning a dam to a different classification, the department shall notify the owner in writing of:

(1) The new classification; and

(2) Any new requirements that might apply as a result of the reclassification.

Env-Wr 303.03 Appeal of Classification.

(a) If the owner disagrees with the department’s decision to reclassify a dam’s hazard classification, the owner may request that the department reconsider the decision.

(b) To request reconsideration, the owner shall submit a written request by first-class mail to the department or via email to: damsafety@des.nh.gov, that includes the following:

(1) The name, mailing address, email address, and daytime telephone number of the owner;

(2) The state dam inventory number assigned by the department, if known, and if not known, the location of the dam by:

a. Tax map and lot number of the property on which the dam is located;

b. A description of the specific location of the dam; and

c. Name of the stream, river, or other water body on which the dam is located, if applicable;

(3) The results of an independent dam breach analysis conducted using the parameters found in Env-Wr 303.02(b) and Env-Wr 502.04; and

(4) An assessment of all structures potentially impacted by a dam failure, including maximum calculated depth of flooding at critical structures or groups of structures.

(c) If the department determines that the information requested in (b) is insufficient to grant the requested reconsideration, the department shall:

(1) Deny the request in writing and provide the reasons for the denial; or

(2) Request that the owner resubmit the request and provide additional information for consideration.

(d) The department shall notify the owner of its decision in writing within 60 days of receiving a complete submittal.

Env-Wr 303.04 Operation, Maintenance, and Response Form.

(a) The owner of a low hazard, significant hazard, or high hazard dam shall complete and submit the "Operation, Maintenance and Response Form" (OMRF) NHDES-W-02-010, May 2024, available at https://onlineforms.nh.gov/?formtag=NHDES-W-02-010.

(b) The owner shall review and update the OMRF as necessary, but no less frequently than after each periodic inspection conducted by the department, and shall submit either an updated form or a statement to the department within 15 days of completing the review, indicating that the current form remains accurate.

(c) The owner shall operate and maintain the dam in accordance with the submitted OMRF and in the best interest of public safety.

Env-Wr 303.05 Emergency Action Plan Required.

(a) As required by RSA 482:11-a, the owner shall develop an emergency action plan (EAP) for any dam where the failure of which might threaten life or property.

(b) In order to facilitate the development of an EAP, the owner may use the EAP template found at the following link: https://www.des.nh.gov/climate-and-sustainability/storms-and-emergencies/dam-emergency-action-plans.

(d) The OMRF completed and submitted by the owner of a low hazard dam pursuant to Env-Wr 303.04, shall constitute the EAP for that dam.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4354, eff 11-30-88; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.06)

Env-Wr 303.06 Dam Repair and Reconstruction.

(a) Pursuant to RSA 482:9, the owner shall not initiate, or authorize anyone else to initiate, work on a dam which qualifies as reconstruction without first obtaining a permit from the department pursuant to Env-Wr 400.

(b) The owner shall consult with the department on any potential modifications or repairs to determine if they meet the definition of reconstruction pursuant to RSA 482:2, X.

(c) An owner wishing to modify the dam so that the impoundment is lowered to a level that reduces potential downstream impacts related to failure and is safe for the dam, shall proceed in accordance with Env-Wr 302.05.

Env-Wr 303.07 Transfer of Ownership.

(a) The owner shall provide the following information to any prospective owner prior to transferring:

(1) Any and all deeds, easements, agreements, or other rights associated with the dam;

(2) The state dam inventory number assigned by the department;

(3) Any letters or orders issued by the department relative to the condition of the dam; and

(4) The existing OMRF.

(b) Within 30 days of the transfer of ownership of a dam or the property on which a dam is located, the new owner shall inform the department in writing of the transfer of ownership by providing the following:

(1) The name of the former owner;

(2) The state dam inventory number assigned by the department;

(3) The name, mailing address, email address, and daytime telephone number of the new owner;

(4) The tax map and lot number of the dam;

(5) The volume and page number of the deed which transferred ownership of the dam or the property on which the dam is located;

(6) An updated OMRF in accordance with Env-Wr 303.04, if the dam is classified as low, significant, or high hazard; and

(7) An updated EAP, if one is required for the dam, in accordance with Env-Wr 500.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4534, eff 11-30-88; rpld by #5080, eff 2-22-91

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.08)

Env-Wr 303.08 Emergency Breach.

(a) An owner may purposefully breach a dam without prior approval from the department only when a threat to public safety or public health exists or significant damage to public or private property is imminent.

(b) The owner shall notify the department and the local emergency management director, police, and fire departments and activate the EAP prior to performing an emergency breach, if possible.

(c) If it is not possible to meet the requirements of (b), above, the owner shall make such notifications as soon as reasonably possible, but never more than one hour after the initiation of the emergency breach.

(d) Within 24 hours of performing an emergency breach, the owner shall confirm with the department that the dam has been stabilized and no longer poses a hazard risk.

(e) Within 90 days of performing an emergency breach, the owner shall file a letter of intent with the department which indicates whether the dam will be:

(1) Reconstructed as defined in RSA 482:2, X and Env-Wr 400;

(2) Removed in accordance with chapter Env-Wr 600; or

(3) Modified in accordance with Env-Wr 302.05.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.09)

Env-Wr 303.09 Other Emergency Measures.

(a) An owner may take measures which otherwise would require a permit to reconstruct a dam, other than emergency breaches, when it is necessary to do so in order to eliminate or reduce the risk of full or partial dam failure. Emergency repairs shall be limited to temporary stabilization of the site or mitigation of the immediate threat.

(b) The owner shall notify the department prior to taking such measures if possible but never more than 24 hours after the initiation of necessary repairs.

(c) Within 48 hours of completing the emergency repairs, the owner shall submit a written statement to the department that explains the nature of the emergency and what corrective measures were taken.

(d) Within 90 days of performing the emergency measure, the owner shall file a letter of intent with the department which indicates whether the dam will be:

(1) Repaired if not reconstructed as defined in RSA 482:2, X;

(2) Reconstructed in accordance with RSA 482:2, X and Env-Wr 400;

(3) Removed in accordance with chapter Env-Wr 600; or

(4) Modified in accordance with Env-Wr 302.05.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.10)

Env-Wr 303.10 Discharge Capacity.

(a) All low hazard, significant hazard, or high hazard dams constructed prior to February 19, 1981 shall pass the flows indicated below with one foot of freeboard and without manual operations:

(1) Low hazard dams shall pass a 50-year design event;

(2) Significant hazard dams shall pass the 100-year design event; and

(3) High hazard dam shall pass the 1,000-year design event, or site specific inflow design flood approved by the department.

(b) All dams constructed after February 19, 1981 shall pass the flow required by the administrative rules in place at the time of the dam’s construction, in accordance with the dam’s current classification, or at the owner's option, the requirements in Env-Wr 303.10(a) above.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.11)

Env-Wr 303.11 Meeting Discharge Capacity Requirements.

(a) If a dam does not have adequate discharge capacity to pass the design event specified in Env-Wr 303.10, the owner shall submit a plan to the department to address the deficiency.

(b) The plan submitted pursuant to (a), above, shall:

(1) Specify the action to be taken, per (c), below; and

(2) Include the results of existing and proposed hydrologic and hydraulic analyses completed pursuant to Env-Wr 403.05 and Env-Wr 403.06, assessing the design event and discharge capacity of the structure.

(1) Increase the capacity of the dam to pass the design event with at least one foot of freeboard and without manual operations;

(2) Submit a stability analysis to the department showing that the dam is safe against sliding or overturning, or other failure mode, as applicable, during the design event pursuant to Env-Wr 303.10, using the methods outlined in “Engineering Guidelines for Evaluation of Hydropower Projects” published by the Federal Energy Regulatory Commission (FERC), Chapter 3 dated 2016, and Chapter 4 dated 2006, available as noted in Appendix B;

(3) Submit a stability analysis to the department showing that the dam is safe against erosion by overtopping during the design event pursuant to Env-Wr 303.10;

(4) Stabilize the dam so that it is safe under the specified design event; or

(5) Modify the dam so that the hazard classification is reduced and the dam passes the design event applicable to the new classification.

(d) The department shall approve the plan if the department determines that:

(1) The proposed action will bring the dam into compliance with Env-Wr 303.10;

(2) The work can be done in a way that will not endanger life or property downstream of the dam; and

(3) The time frame for the work is reasonable under the circumstances, including the risk posed by the deficiency, the owner’s financial resources, and the timing of the work in relation to other uses of the impounded water.

(e) The department shall notify the owner in writing of its decision. If the plan submitted pursuant to (a), above, is not approved, the notice shall specify the reason(s) for denial.

(f) If work under the plan as approved constitutes reconstruction of the dam, the owner shall submit an application for dam reconstruction in accordance with chapter Env-Wr 400.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.12)

Env-Wr 303.12 Request for Time Extension.

(a) An owner may request a time extension to comply with any directive of the department issued pursuant to RSA 482:12.

(b) The request shall be submitted in writing to the department with the following information:

(1) The reason(s) why an extension is needed;

(2) The current status of the repairs or investigations; and

(3) The length of time of extension requested.

(c) The department shall grant the request for time extension if it determines, after review of the information provided in (b), above, that:

(1) The current condition of the dam is such that it is not expected to fail under flow conditions anticipated during the extension; and

(2) The condition of the dam will not deteriorate so as to pose a threat to public safety under flow conditions anticipated during the extension.

(d) The department shall notify the owner of the decision on the request in writing. If the department denies the request, the department shall state the reason(s) for the denial.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 303.13)

Env-Wr 303.13 Maintenance and Operation of Low, Significant, and High Hazard Dams.

(a) Owners of low, significant, and high hazard dams shall undertake the following maintenance activities aimed at promoting dam stability, and safe and consistent operating conditions:

(1) Remove brush, trees, and woody growth from the dam, embankment, and spillway, as applicable, and 15 feet beyond the footprint of the dam. Stumps shall be cut flush to the ground. No trees or large vegetation shall be planted within 15 feet of the footprint of the dam;

(2) Maintain and inspect gate components, valves, flashboards, and other mechanical equipment associated with operation of the dam;

(3) Exercise any gate that is used to routinely control water levels;

(4) Maintain adequate and suitable vegetation or other erosion-resistant ground cover to prevent the erosion of the earthen portions of the dam;

(5) Control, remove, and exterminate rodents, and repair related damage;

(6) Repair earthen embankments, vegetated spillways, and abutments to be free of erosion, depressions, sinkholes, or other deficiencies;

(7) Maintain the crest by:

a. Maintaining a stable base that resists rutting or other damage from routine use and provides for safe access to operate and maintain the dam;

b. Maintaining adequate grade control to prevent ponding and the concentration of surface runoff to unprotected areas; and

c. Grading the crest to eliminate settled areas, depressions, and potholes by filling them with properly compacted material. Grading activities shall not result in raising or lowering the overall crest elevation;

(8) Maintain the intake of horizontal orifices to be free of debris by:

a. Installing a trash rack or grates which shall be sloped or domed and not flat; and

b. Incorporating a bar opening or bar spacing that shall be adequate to efficiently pass smaller debris through the outlet system, but prevent larger debris from entering and clogging the system; and

(9) Repair concrete, wood, metal, and other materials.

Source. #13980, eff 5-24-24

PART Env-Wr 304 NON-PERMITTED EXISTING DAMS

Env-Wr 304.01 Application to Permit Existing Dam.

(a) When the department gains knowledge of the existence of a non-permitted dam, either by its own reconnaissance or by reports of others, it shall send a letter to the owner of the property on which the dam is located stating the non-permitted status of the dam and the requirements with which the owner shall comply.

(b) The department shall include with the letter an "Application for Permit of an Existing Dam," NHDES-W-02-002, May 2024, available at https://onlineforms.nh.gov/?formtag=NHDES-W-02-002, and a copy of RSA 482:5.

(c) Within 30 days of providing notice in accordance with (a), above, the department shall inspect the dam and areas potentially affected by a failure of the dam and provide the owner with an assessment of the dam’s condition and hazard classification.

(d) Upon written notice from the department, the owner shall file the application referenced in (b) above, and include the following information:

(1) The volume and page number at the county registry of deeds of the deed to the dam and of the property on which the dam is located, if different;

(2) The location of the dam on the applicable USGS Quadrangle map;

(3) An "Operation, Maintenance and Response Form” prepared as specified in Env-Wr 303.04;

(4) Plans and specifications which shall, at a minimum, include the following:

a. A scaled plan view;

b. A scaled cross-section view of the dam through the outlet, showing elevations of all features of the outlet system; and

c. Any other plans or information related to the construction of the dam;

(5) The engineer's resume as required by Env-Wr 403.03;

(6) The results of any subsurface explorations;

(7) The results of any structural analyses, which may include but not be limited to, stability analyses for overturning, sliding, and slope failure;

(8) The results of hydrologic and hydraulic calculations, which show that the dam has the capacity to safely discharge the design storm with 1 foot freeboard without manual operations;

(9) A document that proves ownership of flowed land or flowage rights pursuant to Env-Wr 402.02(c)(2);

(10) The results of a seepage analysis for significant and high hazard dams, if applicable;

(11) An EAP for significant and high hazard dams, if applicable; and

(12) Construction plans and specifications.

(e) The owner shall include the following with the application:

(1) The fee required by RSA 482:9, II; and

(2) A statement that the owner has legal flowage rights on all lands which will be permanently or temporarily flooded by the dam and an indication of whether those rights are fee simple ownership, a flowage easement, prescriptive rights, or mill privileges.

(f) The owner shall sign the application and the statement required by (e)(2), above, if such statement is separate from the application.

(g) The owner’s signature shall constitute certification that the information provided is true and complete to the knowledge and belief of the owner.

(h) The owner shall return the completed permit application within 60 days of receiving the letter sent pursuant to (a), above.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 304.02 Inspection. Within 30 days of receipt of the permit application, the department shall inspect the dam and area affected by the dam for conditions and factors affecting the hazard potential classification, and make a determination whether repair or reconstruction of the dam is required for the public safety and provide such information to the owner.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 304.03 Notice to Municipality. Pursuant to RSA 541-A:39, when the department receives an application to permit a non-permitted dam, the department shall issue a notice to the municipality in which the dam is located to invite the municipality to submit data or information pertaining to the department’s assessment of the dam’s potential hazard. If the department receives such correspondence within 30 days of the town’s receipt of the notice, it shall consider the information in issuing a permit.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4534, eff 11-30-88, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 304.04 Issuance of Permit. Subject to Env-Wr 304.05, the department shall issue a permit for the dam pursuant to RSA 482:5 if:

(a) The application is complete, including all information required by Env-Wr 304.01;

(b) The department has determined that the dam’s condition is such that it does not pose an imminent threat to public safety; and

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4534, eff 11-30-88, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 304.05 Limitations on Permit Issuance.

(a) A permit for a significant hazard or high hazard non-permitted dam built on or after July 25, 2000 shall be issued only if the dam meets the criteria established in RSA 482:9, V.

(b) A permit for a dam on a great pond shall be issued only in accordance with RSA 482:6.

Source. #8414, eff 8-20-0; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

CHAPTER Env-Wr 400 CONSTRUCTION OR RECONSTRUCTING A DAM

PART Env-Wr 401 PURPOSE AND APPLICABILITY

Env-Wr 401.01 Purpose. The purpose of this chapter is to implement RSA 482:9 by specifying the procedures for applying for a permit to construct or reconstruct a dam.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-0; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 401.02 Applicability.

(a) Subject to (b), below, the requirements in this chapter shall apply to any person who:

(1) Plans to construct or reconstruct a structure that qualifies as a dam pursuant to Env-Wr 301.02; or

(2) Has taken emergency measures as specified in Env-Wr 303.08 or Env-Wr 303.09.

(b) The requirements in this chapter shall not apply to a dam regulated by the Federal Energy Regulatory Commission (FERC) pursuant to the Federal Power Act, 16 U.S.C. Chapter 12, Subchapter I.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 402 APPLICATION PROCEDURES

Env-Wr 402.01 Application Filing.

(a) An "Application for Permit to Construct or Reconstruct a Dam" form, NHDES-W-02-001, May 2024, available at https://onlineforms.nh.gov/?formtag=NHDES-W-02-001, shall be filed by the owner(s) of the dam, and the owner(s) of the property, if different than the dam owner, on which the dam is proposed to be located.

(b) An application relative to emergency measures pursuant to Env-Wr 303.08 and Env-Wr 303.09, shall be filed by the owner(s) of the dam.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.02 Content of Application.

(a) The applicant shall provide the following information with the application form required in Env-Wr 402.01(a) above:

(1) A statement that the owner has legal flowage rights on all lands which will be permanently or temporarily flooded by the dam and whether those rights are fee simple ownership, a flowage easement, prescriptive rights, or mill privileges;

(2) The volume and page number of the deed for the property on which the dam is or is proposed to be located and, for an existing dam that was conveyed separately from the property, the volume and page number of the deed for the dam;

(3) A description of the specific location of the existing or proposed dam;

(4) The corresponding permit application number or permit number pursuant to RSA 482-A, if applicable;

(5) The size of the drainage area, normal pond area, maximum pond area, normal storage capacity, and maximum storage capacity of the existing or proposed dam;

(6) An OMRF prepared as specified in Env-Wr 303.04;

(7) The engineer's resume as required by Env-Wr 403.03;

(8) The results of any subsurface explorations;

(9) The results of any structural analyses, which may include but not be limited to, stability analyses for overturning, sliding, and slope failure;

(10) The results of hydrologic, hydraulic, and stability calculations, which show that the dam has the capacity to safely discharge the design storm with 1 foot freeboard without manual operations or is safe for overtopping;

(11) A document that proves ownership of flowed land or flowage rights pursuant to Env-Wr 402.02(a)(1);

(12) The results of a seepage analysis for significant and high hazard dams, if applicable;

(13) An EAP for significant and high hazard dams, if applicable; and

(14) Construction plans and specifications.

(b) The owner shall include the following with the application:

(1) The fee required by RSA 482:9, II;

(2) Preliminary plans, specifications and other documentation related to the construction or reconstruction; and

(3) Deeds, easements, rights, or agreements associated with the dam and the property on which the dam is located, if applicable.

(c) The property owner(s) and dam owner(s), if different, shall sign the application to certify that the information provided is true and complete to the knowledge and belief of the signatory(ies).

(d) Incomplete or improperly completed forms shall be returned by the department to the applicant or applicants with a statement for the reason(s) for the return and the additional information required.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.03 Statutory Requirements for Certain Dams.

(a) Pursuant to RSA 482:7, a new dam on a great pond shall not be constructed without specific authorization from the legislature.

(b) The department shall hold a public hearing pursuant to RSA 482:30 and RSA 482:31 upon receipt of an application for construction or reconstruction of dams falling within the scope of RSA 482:17, and conduct the hearing in accordance with the provisions of Env-C 200 relative to non-adjudicative proceedings.

(c) Pursuant to RSA 482:9, V, no permit to construct or reconstruct a significant hazard or high hazard dam shall be issued unless the requirements of that section are met.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.04 Notice to Owner.

(a) Within 10 days of receipt of an application, the department shall provide the owner with the following:

(1) The dam number;

(2) The date of receipt of the application; and

(3) A statement that construction shall not commence until the department and all other appropriate state or federal agencies have granted final approval.

(b) Within 30 days of classification by the department, the department shall provide the owner with the following:

(1) Design and construction requirements for the particular structure depending upon classification; and

(2) Specific information needed for design review per Env-Wr 403 if the submitted design is lacking in particular areas.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.05 Classification Procedure.

(a) The department shall review all new dam applications to classify the structure in accordance with Env-Wr 101.07.

(b) If the owner disagrees with the department’s hazard classification, the owner shall submit, for review by the department, the following:

(1) The results of a dam breach analysis performed in accordance with Env-Wr 303.02 and Env-Wr 502.04;

(2) Breach routing in accordance with Env-Wr 502.05; and

(3) Inundation mapping in accordance with Env-Wr 503.01.

(c) The owner of a proposed dam shall meet specific requirements relative to design, construction, inspection, and maintenance of the structure in accordance with the applicable provisions of Env-Wr 403.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.06 Additional Information Required. If the dam will be a low hazard, significant hazard, or high hazard structure, the owner shall submit plans and specifications which shall, at a minimum, include the following:

(a) Scaled plan view;

(b) Scaled cross-sectional view of dam through the outlet, showing elevations of inlet and outlet, watertight connections, embankment material;

(d) Gradation analysis for all structural soils and fill materials to be used during construction;

(e) Compaction specifications in accordance with Env-Wr 403.02(d) and (e);

(f) Construction sequence;

(g) Sufficient detail to show the location of the proposed work in relation to the entire dam; and

(h) A written OMRF as described in Env-Wr 303.04.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 402.07 Notice to Municipality.

(a) Subject to (b) and (c), below, when the department receives an application to construct or reconstruct a dam, it shall issue a notice to the municipality in which the proposed dam will be located pursuant to RSA 541-A:39, to inform the municipality of the location, height, and size of the impoundment of the proposed dam. The municipality may submit data or information pertinent to the department’s consideration of the application. If the department receives such correspondence within 30 days of the town’s receipt of the notice, it shall consider the information in issuing a permit to construct or reconstruct the dam.

(b) When the department receives an application to construct a new significant hazard or new high hazard structure, the department shall send the notice to the municipality and any municipalities which could be affected by a failure of the dam, and shall include notice of a public informational meeting pursuant to RSA 482:13 to be held by the department in the municipality in which the dam is located or in a municipality that may be affected by a failure of the dam. At the public informational meeting, the owner shall present information about the dam and a draft emergency action plan.

(c) If the application is to construct a new dam on a great pond, the department shall send the notice to all municipalities in which the great pond is located.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 403 SPECIFIC DESIGN REQUIREMENTS

Env-Wr 403.01 Purpose. The purpose of this part is to set forth the minimum design requirements for the construction of new dams and the reconstruction of existing dams.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.02 Design Requirements of All Dams. An application for construction of a new dam or reconstruction of an existing dam shall incorporate the following minimum design requirements:

(a) The embankment slopes shall be no steeper than 2.5 horizontal to 1 vertical unless a specific design for a steeper slope shows that the embankment is stable and capable of being safely maintained;

(b) The embankment top width shall be a minimum of 6 feet;

(d) Soil compaction specifications shall be shown on the plans;

(e) Pre-compacted lift thickness shall be compatible with the material and equipment to be used, but no greater than 12 inches in depth;

(f) A pond drain shall be incorporated for any new dam, except as noted in Env-Wr 403.03(a)(5); and

(g) Trees, brush, and woody growth shall be removed from at least 15 feet beyond the footprint of the manmade structure.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.03 Additional Requirements Based on Hazard Classification.

(a) For the construction or reconstruction of a low hazard, significant hazard, or high hazard dam:

(1) All final plans and design documents shall be stamped by an engineer as defined by Env-Wr 101.16, who shall submit an affidavit attesting to the qualifications in paragraph (2)a.-d., below;

(2) The engineer shall be responsible for the following:

a. Submitting supporting documentation showing relevant experience as a registered engineer in the design, construction, and safety evaluation related to the type of the dam under review;

b. Understanding all applicable regulatory requirements of a dam project and the required work, analyses, and oversight needed to design and observe construction to evaluate compliance with approved plans and specifications for the project;

c. Using current state of the practice methods and means to site and design dams with safety as the primary goal and to complete engineering methodology that represents the professional level of care exercised by qualified engineers; and

d. Assembling and supervising a team of qualified engineers, geologists, geological engineers, and other professionals, as required, to address all of the disciplines for the design and the observation of construction of a dam;

(3) The project shall be inspected in accordance with Env-Wr 405;

(4) A construction inspection plan, prepared in accordance with Env-Wr 405.04, shall accompany the application for construction or reconstruction; and

(5) A design for construction of a new low hazard, significant hazard, or high hazard dam, with the exception of dams impounding liquid industrial, agricultural, or commercial wastes, contaminated sediments or municipal sewage, shall be equipped with a pond drain.

(b) A design for construction or reconstruction of a significant hazard or high hazard dam shall also include the following:

(1) The results of a stability analysis of the structure for overturning, sliding, and slope failure, as applicable, including factors of safety, using the methods outlined in “Engineering Guidelines for Evaluation of Hydropower Projects” published by FERC, Chapter 3 dated 2016 and Chapter 4 dated 2006, available as noted in Appendix B;

(2) The results of a seepage analysis;

(3) The results of subsurface explorations, including, but not limited to borings and test pits; and

(4) A draft breach analysis and draft emergency action plan (EAP), or if an EAP has already been approved, an updated EAP, in accordance with chapter Env-Wr 500.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.04 Design Events for New and Reconstructed Dams.

(a) A new dam shall be designed to safely pass the event indicated below without manual operation and with the freeboard requirements indicated:

(1) A non-menace structure shall pass the 50-year design event or, at the owner’s option, the site-specific inflow design flood, with at least one foot of freeboard;

(2) A low hazard structure shall pass the 100-year design event or, at the owner’s option, the site-specific inflow design flood, with at least one foot of freeboard;

(3) A significant hazard structure shall pass ½ of the probable maximum flood (PMF) as determined using Hydrometeorological Report No. 52 (HMR 52) from the National Oceanic and Atmospheric Administration (NOAA), 1982, available as noted in Appendix B, or the site-specific inflow design flood; and

(4) A high hazard structure shall pass the PMF as determined using HMR 52, 1982, available as noted in Appendix B, or the site-specific inflow design flood.

(b) A reconstructed dam shall be designed to safely pass the flows identified in Env-Wr 303.10, as applicable.

(c) The owner shall submit the results of calculations performed for hydrologic and hydraulic analyses pursuant to (a) and (b), above, and Env-Wr 403.05 and Env-Wr 403.06 with the application.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.05 Hydrologic and Hydraulic Investigations.

(a) Hydrologic and hydraulic investigations shall be performed on the entire contributing drainage area using one of the references below:

(1) The NRCS National Engineering Handbook, Part 630, Hydrology, Chapters 4, 6-10, 14-17, dated March 2020, available as noted in Appendix B;

(2) The U.S. Army Corps of Engineers’ Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) version 4.11, available as noted in Appendix B;

(3) The U.S. Army Corps of Engineers’ Hydrologic Engineering Center River Analysis System (HEC-RAS) version 6.3.1, available as noted in Appendix B; or

(4) HydroCAD Stormwater Modeling version 10.2, available as noted in Appendix B.

(b) Precipitation estimates for estimating the design flood shall be obtained from:

(1) Extreme Precipitation in a Changing Climate for New York and the New England States”, version 2.0, published by the USDA, NRCS and Cornell University’s Northeast Regional Climate Center, available as noted in Appendix B;

(2) “NOAA Atlas 14, Precipitation-Frequency Atlas of the United States”, Volume 10, Version 3.0, 2019, published by the National Oceanic and Atmospheric Administration, National Weather Service, available as noted in Appendix B; or

(3) U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Hydrometeorological Report No. 51, Probable Maximum Precipitation Estimates, United States East of the 105^th Meridian, June 1978, available as noted in Appendix B.

(c) A report describing the hydrologic and hydraulic analyses shall be submitted to the department and shall include the following:

(1) A summary narrative of the project;

(2) A description of the drainage area;

(3) Time of concentration calculations;

(4) Curve number calculations;

(5) Storage calculations;

(6) Discharge rating curve calculations;

(7) Flashboard calculations;

(8) Any other calculations or assumptions used in developing the models;

(9) Drainage area plans which delineate each sub-basin identifying the following:

a. The location and size in acres of sub-basins, reaches, ponds, and storage areas, and all points of interest, included in the model;

b. Hydrologic soils groups obtained from the NRCS/USDA web soil survey at USDA Web Soil Survey, available as noted in Appendix B; and

c. Land cover;

(10) All error messages, warnings, and other such indicators provided by the software model, with explanations for their occurrence, as applicable; and

(11) All electronic files required for the department to run and assess the accuracy of the models.

(d) The storm duration used in the modeling shall exceed the time for water to flow from the outermost point in the system to the subject location, but shall be no less than 24 hours, so as to ensure that the total runoff volume will be included in the routing of the storm through the dam structure.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.06 Additional Reference for Hydraulic Determination. The department shall use the “Handbook of Hydraulics”, Eighth Edition, 2017, available as noted in Appendix B, in evaluating the competence of the submitted design.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.07 Concrete Design Criteria. The department shall use one or more of the following texts in evaluating the competence of the submitted design:

(a) “Building Code Requirements for Structural Concrete & Commentary,” ACI 318-19(22), American Concrete Institute, 2022, available as noted in Appendix B for anchor design; or

(b) “Code Requirements for Environmental Engineering Concrete Structures and Commentary,” ACI-350-20 and ACI 350R-20, American Concrete Institute, 2020, available as noted in Appendix B, for concrete design.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.08 Steel Design Criteria. The department shall use the “Steel Construction Manual” by the American Institute of Steel Construction, Fifteenth Edition, 2017, available as noted in Appendix B, in evaluating the competence of the submitted design.

Source. #8414, eff 8-20-0; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.09 Timber Design Criteria. The department shall use one or more of the following texts in evaluating the competence of the submitted design:

(a) “Timber Construction Manual” by the American Institute of Timber Construction, Sixth Edition, dated 2012, available as noted in Appendix B; or

(b) “2018 National Design Specification for Wood Construction” by the American Wood Council, dated 2018, available as noted in Appendix B.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 403.10 Earth Embankment Design Criteria. The department shall use one or more of the following texts in evaluating the competence of the submitted design:

(a) USDA NRCS Earth Dams and Reservoirs Technical Release 210-60 (TR 210-60), 2019, available as noted in Appendix B;

(b) Evaluation and Monitoring of Seepage and Internal Erosion” FEMA P-1032, May 2015, available as noted in Appendix B;

2011, available as noted in Appendix B;

(d) “Technical Manual: Conduits through Embankment Dams” FEMA L-266, September 2005, available as noted in Appendix B;

(e) “Technical Manual: Overtopping Protection for Dams” FEMA P-1015, 2014, available as noted in Appendix B;

(f) “Technical Manual: Plastic Pipe Used in Embankment Dams” FEMA P-675, November 2007, available as noted in Appendix B; or

(g) NRCS “National Engineering Handbook”, Part 628, Articulated Concrete Block Armored Spillways, March 2019, as noted in Appendix B.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 404 ISSUANCE AND CONDITIONS OF PERMITS

Env-Wr 404.01 Approval.

(a) Subject to (b) and (c), below, the department shall approve an application to construct or reconstruct a dam if:

(1) The requirements of Env-Wr 402 and Env-Wr 403 have been met; and

(2) Issuance of the permit is consistent with RSA 482:1 and any other applicable provisions of RSA 482.

(b) If the proposed dam is a new dam on a great pond, the application shall not be approved until the owner has been granted authority by the legislature to construct or reconstruct the dam in accordance with RSA 482:7.

(c) If the dam is proposed under RSA 482:17, the application shall not be approved until the department has determined after holding a non-adjudicative hearing in accordance with the applicable provisions of Env-C 200 that it is in the public benefit to grant the permit pursuant to RSA 482:31.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 404.02 Issuance and Recordation of Permit/Registration.

(a) Upon review and approval of the application, the department shall issue a permit authorizing the construction or reconstruction. The permit shall include any restrictions, requirements, or disclaimers as specified in Env-Wr 404.03.

(b) The department shall send the original permit to the registry of deeds for the county in which the dam is located to be recorded.

(c) The department shall send a copy of the permit to the owner at the time of approval. The department shall send the original permit to the owner upon receipt from the registry of deeds.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 404.03 Conditions of Permit. The following conditions shall apply to all permits to construct or reconstruct a dam:

(a) The permit shall be valid for 5 years from the date of issuance;

(b) Work under the permit shall be completed within 5 years unless the owner has requested and received a time extension in accordance with Env-Wr 404.04;

(c) All work on the dam shall comply with the approved plans and specifications, subject to design changes approved and documented in accordance with Env-Wr 404.05;

(d) The engineer shall provide a final inspection report in accordance with Env-Wr 405.07;

(e) The engineer shall certify to the department that the work was completed in accordance with the approved plans and specification and design intent as required by Env-Wr 405.08;

(f) Inspections shall be performed in accordance with the plan submitted pursuant to Env-Wr 405.04;

(g) The owner shall notify the department upon completion of the work in accordance with Env-Wr 405.10(a);

(h) The owner shall maintain a current mailing and email address with the department;

(i) The owner shall operate and maintain the structure in accordance with the written approved OMRF procedures submitted in accordance with Env-Wr 402.06(a)(8); and

(j) The department shall include in the permit any other conditions necessary to ensure protection of public safety that are based on the specific design, site, and watershed.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-0; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 404.04 Time Extension. The department shall grant a single 2-year time extension to construct or reconstruct a dam if:

(a) The owner requests the extension in writing prior to the permit’s expiration date;

(b) The hazard classification of the dam has not changed; and

(c) The approved plans meet current design requirements or have been amended to meet current requirements in accordance with Env-Wr 404.05.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 404.05 Design Changes.

(a) No changes shall be made to the plans and specifications approved by the department, either before or during construction, unless:

(1) The changes are approved by the engineer; and

(2) The changes are approved by the department in writing or electronic mail.

(b) To request a change, the owner or the engineer shall submit a request for the change in writing or electronic mail to the department, which shall include:

(1) The specific information regarding the requested change, including supporting documentation, as needed; and

(2) The reason the change is being requested.

(c) The department shall approve the change if the overall design as revised would have been approved if it had been submitted as part of the application.

(d) The department shall notify the owner and the engineer, if applicable, of the decision on the request in writing or electronic mail. If the request is denied, the decision shall state the reason(s) for the denial.

(e) If time is of the essence, the department shall convey verbal approval prior to issuing written or electronic mail approval.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 405 DAM CONSTRUCTION INSPECTIONS

Env-Wr 405.01 Purpose. The purpose of this part is to set forth the requirements for inspections to be conducted during dam construction or reconstruction.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.02 Applicability. These rules shall apply to inspections which are required during construction and reconstruction of a low hazard, significant hazard, or high hazard dam pursuant to RSA 482:11.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.03 Engineer for Construction.

(a) Prior to starting any work related to construction or reconstruction, the owner shall engage an engineer to ensure compliance with approved plans and specifications during construction.

(b) The engineer shall comply with the requirements of Env-Wr 403.03(a)(2) a. through d.

(1) The accurate completion of all inspection tasks; and

(2) Compliance with approved plans and specifications.

(d) The engineer may assign some inspection tasks to a duly-authorized and qualified agent provided that the agent’s inspection tasks are explicitly identified in the construction inspection plan described in and submitted pursuant to Env-Wr 405.04. The engineer shall be responsible for ensuring that the agent is qualified to perform the duties assigned.

(e) Prior to starting any work related to construction or reconstruction, the engineer responsible for performing the inspections shall complete and submit "Dam Construction Inspection Engineer Acknowledgement Form," NHDES-W-02-011, May 2024, available at https://onlineforms.nh.gov/?formtag=NHDES-W-02-011.

(f) The engineer’s signature shall constitute certification that they have reviewed the plans, specifications, supporting assumptions, and design calculations, and other documentation related to the design and construction and understands the design and the intent of the design.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.04 Inspections During Construction or Reconstruction.

(a) Prior to starting any work related to construction and reconstruction, the owner shall submit a written construction inspection plan to the department.

(b) The plan required by (a) above shall include, but not be limited to, the following:

(1) Which construction activities shall be monitored the engineer or the duly-authorized and qualified agent, if employed;

(2) Field tests to be performed and the frequency of testing;

(3) Material testing requirements; and

(4) Documentation and reporting requirements, including weekly progress reports and construction photographs.

(c) The department shall approve the plan if it determines that the plan is adequate to ensure that the dam will be constructed or reconstructed in accordance with the approved plans and specifications.

(d) Inspections during construction or reconstruction shall be performed in accordance with the approved inspection plan.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.05 Work Items to be Inspected. The engineer or agent shall inspect, verify the adequacy of, document, and photograph, at a minimum, the following work items:

(a) Excavation and sub-grade preparation;

(b) Pipe placement and bedding material;

(d) Placement of earthfill;

(e) Cut-off construction;

(f) Steel placement, rebar and structural steel;

(g) Overtopping protection;

(h) Final grading; and

(i) Placement of concrete.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.06 Inspection Frequency. The frequency of inspections for construction and reconstruction projects shall be as frequent as needed to ensure compliance with approved plans and specifications and in accordance with the requirements of the approved construction inspection plan.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 405.07 Final Inspection Report.

(a) The engineer shall submit an inspection report to the department within 60 days of the completion of the project.

(b) The report shall include:

(1) A copy of all test results;

(2) The engineer’s and agent’s, if one or more are employed, observations of the work items specified in Env-Wr 405.05;

(3) Summary of weekly progress reports for all inspections, including representative photographs;

(4) Documentation of all department-approved changes in design;

(5) Foundation conditions observed during excavation; and

(6) Any other data pertinent to determining the integrity of the structure, including unexpected conditions or unusual circumstances observed during the project.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 405.08)

Env-Wr 405.08 Affidavit of Compliance. Prior to filling the reservoir, the engineer shall provide the department with an affidavit of compliance indicating that the construction or reconstruction was completed in accordance with approved plans, specifications, and the intent of the design, including any design changes approved in accordance with Env-Wr 404.05.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; rpld by #6462-B, eff 2-21-97

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 405.09)

Env-Wr 405.09 As-built Drawings. The engineer shall submit as-built drawings of the project to the department within 180 days of submitting the affidavit of compliance.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 405.10)

Env-Wr 405.10 Requirements Prior to Impounding.

(a) The owner shall notify the department in writing or by electronic mail upon the completion of construction or reconstruction of any low hazard, significant hazard, or high hazard dam and prior to filling the reservoir. The notice shall include the state dam inventory number and the location of the dam.

(b) Within 10 working days of receipt of notice from the owner, the department shall perform a final visual inspection with the reservoir drained, and either authorize filling of the reservoir by issuance of a certificate of approval or order remedial action for noncompliance with the approved plans and specifications.

(c) No person shall close gates or take other actions that cause the dam to impound water until the owner is authorized by the department to fill the reservoir.

(d) The department shall authorize the owner to fill the reservoir only after the department:

(1) Receives the affidavit of compliance as required by Env-Wr 405.08;

(2) Performs a final visual inspection of the dam;

(3) Issues a certification of approval; and

(4) Verifies that the final EAP has been approved and distributed to all EAP holders, and a successful test of the notification flowchart has occurred, if applicable.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 405.11)

CHAPTER Env-Wr 500 EMERGENCY ACTION PLANS

PART Env-Wr 501 PURPOSE AND APPLICABILITY

Env-Wr 501.01 Purpose and Applicability.

(a) The purpose of the rules in this chapter is to establish the requirements for an emergency action plan (EAP), whose purpose is to assist emergency responders in the event of a specific dam failure by:

(1) Delineating the area which could be inundated;

(2) Providing notification procedures; and

(3) Identifying the responsibilities of individuals or agencies in a response.

(b) Subject to (c) and (d), below, the owner shall prepare an EAP in accordance with these rules for any high or significant hazard dam.

(c) EAPs for dams subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) shall be prepared in accordance with FERC requirements and a copy filed with the department.

(d) EAPs for the following U.S. Army Corps of Engineers (USACE) dam projects shall be prepared in accordance with USACE requirements and a copy filed with the department including:

(1) Franklin Falls Dam;

(2) Blackwater Dam;

(3) Hopkinton-Everett Dams;

(4) Edward MacDowell Dam;

(5) Otter Brook Dam; and

(6) Surry Mountain Dam.

PART Env-Wr 502 BREACH ANALYSIS

Env-Wr 502.01 When Required. Unless exempted pursuant to Env-Wr 502.02, the owner shall have a dam breach analysis performed in accordance with this part prior to preparing an EAP.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 502.02 Exemption from Breach Analysis.

(a) Subject to (c), below, an owner shall be exempted from the development of a breach analysis if the department determines that the hazard classification is based solely on the potential damage to one or more isolated and easily identified bridges, roadways, or other structures located below the dam.

(b) If this exemption applies to a dam, the department shall:

(1) Notify the owner in writing or by electronic mail of the exemption; and

(2) Inform the owner of the exact structures to be delineated on a simplified inundation map, as required by Env-Wr 503.02.

(c) If conditions downstream of the dam change such that additional bridges, roadways, or other structures would be affected by a dam failure and these structures are not isolated and easily identifiable, the department shall notify the owner in writing that the exemption has been repealed and a dam breach analysis, as described in Env-Wr 502.04, shall be required due to the new developments downstream of the dam.

Env-Wr 502.03 Breach Analysis Required Due to Reconstruction. The owner shall complete a new or revised breach analysis, as applicable, to ascertain the impacts of a dam failure if:

(a) The dam is reconstructed, resulting in a higher normal pool level or an increase in impoundment storage;

(b) A change in structural configuration could result in failure modes that reduce or increase the effects of a dam failure; or

Env-Wr 502.04 Specific Requirements and Breach Parameters.

(a) The dam breach analysis shall be performed under the direction of and stamped by an engineer licensed in New Hampshire and experienced in hydrology, hydraulics, and breach modeling.

(b) The breach parameters shall be in accordance with Table 5.1 and Figure 5.1 below, unless the department approves the use of other parameters pursuant to (c), below:

Table 5.1 Dam Breach Parameters

PARAMETER	TYPE OF DAM	VALUE
Average Width of Breach (BR)	Arch	BR = Crest Length
	Masonry, Gravity	BR = Width of one or more monoliths, usually BR ≤0.5 W
	Earth, Rockfill, Timber Crib	HD ≤ BR ≤ 5HD (usually between 2HD and 4HD)
Horizontal Component of Side Slope of Breach (Z)	Arch	0 ≤ Z ≤ slope of valley walls
	Masonry, Gravity	Z = 0
	Earth, Rockfill, Timber Crib	1/4 ≤ Z ≤ 1
Time to Failure (TFH) in hours	Arch	TFH ≤ 0.1
	Masonry, Gravity	0.1 ≤ TFH ≤ 0.3
	Earthen (Engineered, Compacted) Timber Crib	0.1 ≤ TFH ≤ 1.0
	Earthen (Non-Engineered, Poor Construction)	0.1 ≤ TFH ≤ 0.5

Diagram

Description automatically generated

(c) The department shall allow use of different parameters due to specific dam or site conditions, if the dam owner demonstrates by clear and convincing evidence that the use of the alternative parameters would result in an accurate model and would not underestimate the effects of a dam failure.

(d) A dam breach flow shall be routed together with each of the following base flows:

(1) The sunny day flow;

(2) The 50-year design event; and

(3) The 100-year design event.

(e) The breach flow together with the base flows in (d), above, shall:

(1) Be routed downstream of the dam with downstream inflows; and

(2) Include provisions to identify the number of hours or minutes from the start of a failure to the time when the river initially starts to rise, breach wave arrival time, and the time to reach peak stage, time to peak.

(f) Peak flow velocities also shall be determined and shown on the inundation map for critical stations such as road crossings and populated areas below the dam.

(g) The routing shall continue downstream until the point at which the water surface elevation due to dam failure is 1 foot above the non-failure conditions in areas of potential threat to life and major property damage.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4580, eff 2-27-89; ss by #5080, eff 2-22-91; ss by #6462-B, eff 2-21-97; ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 502.06)

Env-Wr 502.05 Breach Modeling Methods.

(a) The owner shall use the U.S. Army Corps of Engineers’ Hydrologic Engineering Center River Analysis System (HEC-RAS), version 6.3.1, available as noted in Appendix B, for dam breach analysis modeling.

(b) An owner wishing to use other techniques for breach modeling shall submit a written request for approval of the technique to the department for each particular site prior to using the technique. The request shall contain a description of the technique, including how the technique addresses the parameters addressed by the techniques identified in (a), above.

(c) If the department determines that the technique can be correctly applied to the hydrologic and topographic conditions of the dam and downstream area, within the limitations and capabilities of the modeling technique, and that it will provide the detailed information required by these rules, the department shall approve the technique for use on that site and shall so notify the owner in writing.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 502.06 Downstream Dams.

(a) When there are dams downstream located within the study area as determined by Env-Wr 502.04(g), the owner shall evaluate the effect of the breach flow on these dams.

(b) If a downstream dam would not be overtopped by failure of the subject dam, no stability analysis of this structure shall be required.

(1) Include the downstream dam’s failure in the breach model; or

(2) Submit to the department the results of a stability analysis for overturning, sliding, or other applicable failure mode, as applicable, including factors of safety, for the downstream dam.

(d) If the stability analysis performed pursuant to (c)(2), above, indicates that a downstream dam is unstable during overtopping for the duration of the event, the owner shall include the failure of the downstream dam in the breach model.

(e) If the stability analysis performed pursuant to (c)(2), above, indicates that a downstream dam is stable during overtopping for the duration of the event, its failure shall not be required to be modeled in the dam breach analysis.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 502.08)

Env-Wr 502.07 Review of Breach Analysis by Department.

(a) The owner shall submit the following information to the department for review:

(1) A narrative describing the structural and hydraulic breach assumptions and base flow criteria;

(2) A description of the methods for determining downstream inflows;

(3) Structural stability analyses of downstream dams, if applicable;

(4) Summary of the results of the breach analysis, both narrative and tabular;

(5) A Geographic Information System shapefile; and

(6) All electronic modeling files for the analysis required for the department to run and review the model.

(b) The owner shall submit draft inundation maps prepared in accordance with Env-Wr 503 with the information listed in (a), above.

(c) If the information submitted pursuant to (a) and (b), above, is incomplete or the dam failure is incorrectly modeled, the department shall, within 60 days of receipt of the information, notify the owner in writing of the items which need to be addressed and the deadline for submittal of the amended analysis, which shall be 60 days from the date of the department’s response.

(d) If the information submitted pursuant to (a), above, is complete and failure is correctly modeled, the department shall, within 60 days of receipt of the submitted information, approve the breach analysis submittal.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 502.09)

PART Env-Wr 503 INUNDATION MAPPING

Env-Wr 503.01 Inundation Map Requirements.

(a) The owner shall produce an inundation map in pdf format to provide the local emergency responders with a tool for planning evacuation procedures.

(b) The inundation map shall delineate the area impacted by a potential dam failure, as determined by the breach analysis required by Env-Wr 502.

(1) The map(s) shall be at an appropriate scale to show sufficient detail of all impacted areas, but at a minimum scale of 1:2,000;

(2) Residences, commercial, and industrial structures or clusters of structures, when located in close proximity to each other within the inundation area shall be shown on the most current aerial photography available at the time the map is produced;

(3) Roads within the inundation area and within at least 0.5 mile from the exterior boundary of the inundation area shall be shown and clearly labeled;

(4) The breach wave arrival time and breach wave peak time for critical areas including, at a minimum, those outlined in (2) and (3), above, shall be shown;

(5) Peak breach wave velocities at critical areas shall be shown;

(6) Peak breach wave depths above ground surface at critical structures and areas shall be shown with specific reference to depths of flooding above first floor elevations of habitable structures when present;

(7) City or town boundaries shall be shown;

(8) The map(s) shall depict the inundation area of both the sunny day flow failure and the 100-year design event flow failure scenarios;

(9) The date on which the map was prepared shall be included on the map; and

(10) The date that the breach analyses for the inundation depicted on the map(s) were approved by the department.

(d) If the inundation map set consists of 3 or more pages, an index map shall be provided which clearly directs the user to the appropriate map for a given area.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; rpld by #4534, eff 11-30-88

New. #6462-B, eff 2-21-97 (from Env-Wr 504.01); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-04; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 503.02 Simplified Inundation Map.

(a) An owner who has been exempted from the requirement of a breach analysis pursuant to Env-Wr 502.02 shall submit a simplified inundation map.

(b) The simplified inundation map shall include the elements specified in Env-Wr 503.01(a), (c)(1) - (3), (c)(7), and (c)(9).

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 503.03 Department Review.

(a) The owner shall submit the inundation map(s) to the department for review and approval prior to incorporating it into the EAP.

(b) The department shall inform the owner in writing within 30 days of receipt whether the inundation map is approved or of any inadequacies requiring revision and resubmission.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 504 PREPARATION AND FORMAT OF EAP DOCUMENT

Env-Wr 504.01 Submittal of Draft EAP.

(a) The owner shall submit a copy of the draft EAP prepared pursuant to Env-Wr 504.02 to the department for review.

(b) The department shall review the document for compliance with this chapter and, within 60 days of submittal, notify the owner in writing of its approval of the EAP or of any inadequacies requiring revision and resubmission.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; amd by #4580, eff 2-27-89; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.01); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.01)

Env-Wr 504.02 Format of the EAP.

(a) The EAP shall be submitted on 8½ x 11 paper, hard copy, and in pdf format.

(1) Table of Contents;

(2) Section 1, Notification Flowchart;

(3) Section 2, General Responsibilities;

(4) Section 3, Preventive Action; and

(5) Appendices, including:

a. Appendix A, Project Description;

b. Appendix B, Impact of Breach;

c. Appendix C, Inundation Map; and

d. Appendix D, Posting of the Plan.

(d) The required contents of each section or appendix shall include the information identified in Env-Wr 504.03 through Env-Wr 504.09, as applicable.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4452, eff 8-1-88; amd by #4580, eff 2-27-89; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.02); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.02)

Env-Wr 504.03 Notification Flowchart.

(a) Section 1 of the EAP shall be a chart identifying the individuals and local and state government agencies to be notified during a potential or actual emergency condition at the dam.

(b) The notification flowchart shall be developed in coordination with local and state emergency responders and shall conform with the community’s current notification protocol of each.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.03); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.03)

Env-Wr 504.04 General Responsibilities. Section 2 of the EAP shall describe the roles and responsibilities of each individual or entity identified in the notification flowchart.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.04); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.04)

Env-Wr 504.05 Preventive Action. Section 3 of the EAP shall:

(a) Indicate actions that the owner or designee shall take to operate the dam or to address or correct a malfunction of the dam;

(b) Identify the means, materials, and equipment needed to address anticipated malfunctions or make emergency repairs to the dam;

(c) Identify the necessary equipment, including alternative power sources, to operate the dam’s outlet works or other essential components; and

(d) Include any other preventive and mitigative action measures to be undertaken during emergency situations.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.05); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.05)

Env-Wr 504.06 Project Description. Appendix A of the EAP shall include the following information:

(a) Height of the dam, in feet;

(b) Normal surface area of the impoundment, in acres;

(d) Drainage area upstream of the dam, in acres;

(e) Primary spillway freeboard, in feet; and

(f) Discharge capacity of the dam assuming no manual operations with water level one foot from the top of the dam, in cubic feet per second.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.06); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.06)

Env-Wr 504.07 Impact of Breach. Appendix B of the EAP shall be a summary of the breach impacts associated with a failure of the dam under both the sunny day flow and 100-year design event conditions. The summary shall be written so as to be easily understood during an actual emergency, in order to provide emergency responders with a clear and concise description of the areas downstream of the dam which would be affected by a dam failure in each of the breach scenarios.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.07); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 505.08)

Env-Wr 504.08 Inundation Map. Appendix C of the EAP shall include the inundation map(s) developed in accordance with Env-Wr 503, as applicable.

Source. #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.08); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 504.09 Posting of the Plan. Appendix D shall include, at a minimum, the telephone numbers and email addresses of all of the following individuals, entities, and local and state agencies holding official copies of the EAP:

(a) The local emergency responders, including police and fire departments;

(b) The regional and local dispatcher(s) for local emergency responders;

(d) The New Hampshire department of safety, division of emergency services and communications (911);

(e) The New Hampshire department of environmental services, division of water, dam bureau;

(f) The New Hampshire department of safety, division of state police;

(g) The New Hampshire department of transportation, division of operations, transportation systems, management & operations;

(h) The appropriate district office(s) of the New Hampshire department of transportation, division of operations, bureau of highway maintenance;

(i) The New Hampshire department of safety, division of homeland security and emergency management; and

(j) Any other person or entity included on the notification flowchart included in the EAP.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84; ss by #4534, eff 11-30-88; ss by #5080, eff 2-22-91; ss and moved by #6462-B, eff 2-21-97 (formerly Env-Wr 506.09); ss by #8285, INTERIM, eff 2-21-05, EXPIRES: 8-20-05; ss by #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 505 FINAL DISTRIBUTION; PUBLIC NOTICE

Env-Wr 505.01 EAP Distribution. Upon receiving department approval of the draft EAP pursuant to Env-Wr 504.01, the owner shall distribute the approved EAP to persons and entities, as identified in Env-Wr 504.09.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 506.01)

Env-Wr 505.02 Public Notice. If the local community(ies) request information relative to the EAP to be shared with the general public, the owner shall cooperate by participating in any informal meeting held by the local community(ies) at a location near the dam or the inundation area and by providing relevant information.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 506.02)

PART Env-Wr 506 TESTING AND UPDATING PROCEDURES

Env-Wr 506.01 Notification Test.

(a) Prior to conducting a test of the notification flowchart, the owner shall review the EAP and if any changes are needed, the owner should proceed in accordance with Env-Wr 506.02 before initiating the test.

(b) The owner shall conduct a test of the notification flowchart within one month of approval of the EAP and every 2 years thereafter for a high hazard dam and every 4 years thereafter for a significant hazard dam.

(c) The test shall consist of the owner making the primary contact as shown on the flowchart and indicating that a required test of the EAP is being conducted.

(d) Within 7 days of conducting the test, the owner shall either:

(1) Notify the department after verifying that a successful test occurred by contacting the final contact in each flowline of the notification flowchart. The portion of the notification flowchart with calls initiated by the New Hampshire state police need not be included in the verification process; or

(2) Notify the department that the test was unsuccessful and within 30 days of the notification, determine where problems occurred, modify the notification flowchart and other portions of the EAP, as necessary, distribute updated material to all EAP holders, and repeat test. Following completion, notify the department pursuant to (d)(1), above.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 507.01)

Env-Wr 506.02 EAP Review and Changes.

(a) If the owner becomes aware of any changes necessary to the notification flowchart, either as a result of the notification test or by other means, the owner shall:

(1) Make the changes to the notification flowchart and in other portions of the EAP that related to these changes as necessary; and

(2) Distribute updated flowcharts to all holders of the EAP.

(b) The owner shall review the entire EAP annually to ensure its accuracy.

(1) Revise the EAP in accordance with chapter Env-Wr 500 to reflect these changes; and

(2) Distribute the updated EAP to all holders of the EAP.

(d) The owner shall submit written documentation or email confirmation to the department that the annual review of the EAP was performed, by providing one of the following:

(1) A statement that the EAP was reviewed and that no changes to the EAP are necessary; or

(2) An electronic copy in pdf format of the entire, revised EAP and confirmation that the revised EAP has been distributed to all holders of the EAP.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24 (formerly Env-Wr 507.02)

CHAPTER Env-Wr 600 REMOVAL OF DAMS

PART Env-Wr 601 PURPOSE AND APPLICABILITY

Env-Wr 601.01 Purpose. The purpose of the rules in this chapter is to specify the procedures to be followed when proposing to remove a dam under the auspices of the department’s river restoration program and the criteria that will be applied in reviewing such proposals.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 601.02 Applicability. The requirements of this part shall apply to any person who seeks to remove a dam under the auspices of the department’s river restoration program.

Source. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 602 DAM REMOVAL PROPOSALS

Env-Wr 602.01 Qualifying Removals.

(a) In order to qualify as a dam removal under this chapter, the structure shall be removed:

(1) To at least the depth of the natural streambed elevation; and

(2) Subject to (b) through (d), below, to the width of the free-flowing ordinary high-water mark of the river or stream in the area of the footprint of the dam from bank to bank.

(b) The person seeking to remove a dam pursuant to this chapter may request the department to approve a narrower opening by submitting the request in writing with the following:

(1) The width of the free-flowing ordinary high-water mark of the river or stream in the area of the footprint of the dam from bank to bank, in feet;

(2) The width of the proposed opening, in feet, at:

a. The natural streambed elevation;

b. The ordinary high-water mark line and elevation; and

c. The widest point of the opening, if other than the natural streambed elevation or ordinary high-water mark;

(3) The shape of the proposed opening; and

(4) An explanation of how the narrower opening will meet the criteria specified in (d), below.

(c) In addition to the information provided in (b)(1)-(4) above, a hydrologic and hydraulic analyses completed pursuant to Env-Wr 403.05 and Env-Wr 403.06 shall be provided, upon request by the department, in order to demonstrate that the remaining portions of the dam, if any, no longer qualify as a jurisdictional dam in accordance with RSA 482:2, II.

(d) The department shall approve the request for a narrower opening if the department determines that:

(1) The structure will no longer be considered a dam as defined in RSA 482:2, II;

(2) The remains of the dam between the ordinary high-water marks on both sides of the river will not create a safety hazard to the public when using the river;

(3) The natural flow of sediment and nutrients will not be impeded; and

(4) The passage of fish and other aquatic species will not be impeded.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 602.02 Dam Removal Proposal. The person seeking to remove a dam shall complete and submit:

(a) An application for a permit as required under RSA 482-A and Env-Wt 100 et seq., including the plans and specifications required for that application; and

(b) A "Dam Removal Project Attachment for the Wetlands Application" form, NHDES-W-02-003, May 2024, available at https://onlineforms.nh.gov/?formtag=NHDES-W-02-003.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 602.03 Attachments for Dam Removal Projects. The following information shall be provided as an attachment to the form required in Env-Wr 602.02(b):

(a) A description of the proposed methods to remove the dam, including construction sequence, so as to meet the criteria of Env-Wr 602.01 and Env-Wr 604.01(a);

(b) An explanation of the purpose for removing the dam;

(c) Plans showing removal design and restoration of site, including existing conditions, plan view, and a cross section of dam to be removed;

(d) Description of method and location of disposal of dam materials;

(e) USGS topographic map with property lines indicated;

(f) Tax map showing property lines and the abutters' properties labeled;

(g) Original, dated photos mounted or digital copies on 8.5" x 11" sheets of paper clearly illustrating the project impact area with locations of photographs noted on the plans, required in (c) above; and

(h) Plans depicting the information required in Env-Wr 602.01(a).

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 603 NOTIFICATION

Env-Wr 603.01 Notification. An owner proposing to remove a dam impounding 10 acres or more shall comply with the requirements of RSA 211:11 and RSA 482:13.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 604 APPROVAL; REPORT

Env-Wr 604.01 Dam Removal Approval.

(a) The department shall approve the removal of the dam if the applicant:

(1) Proposes a dam removal project that meets the criteria of Env-Wr 602.01; and

(2) Demonstrates that the dam removal will be performed in a manner that:

a. Will not cause damage to structures downstream of the dam; and

b. Will not cause environmental damage that cannot self-restore within one year.

(b) The department shall notify the applicant and the owner, if the applicant is not the owner, in writing of its decision.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 604.02 Post-Removal Report. Upon completion of the removal, the person removing the dam shall file with the department a written statement certifying that the removal was completed in accordance with the approved plans and specifications.

Source. #1716, eff 2-20-81; ss by #2207, eff 12-13-82; ss by #2900, eff 11-7-84, EXPIRED 11-7-90

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

CHAPTER Env-Wr 700 LAKE LEVEL DETERMINATIONS

PART Env-Wr 701 PURPOSE AND APPLICABILITY

Env-Wr 701.01 Purpose. The purpose of the rules in this chapter is to specify the procedures to be followed when a lake level investigation is conducted pursuant to RSA 482:79.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 701.02 Applicability. The requirements of this chapter shall apply to any lake level investigation initiated pursuant to RSA 482:79.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05; ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 702 REQUEST; PRELIMINARY INVESTIGATION

Env-Wr 702.01 Formal Request.

(a) A request for a lake level investigation pursuant to RSA 482:79 shall be:

(1) In writing; and

(2) Mailed or delivered to the department at the following address:

Lake Level Determination Request

Department of Environmental Services

Water Division

29 Hazen Drive

P.O. Box 95

Concord, NH 03302-0095

(b) The request shall state clearly the reason(s) for the request.

(c) The request shall be signed by at least 10 property owners whose land abuts the water body whose water level is the subject of the request.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.01); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 702.02 Preliminary Investigation.

(a) As required by RSA 482:79, the department shall commence a preliminary investigation of conditions affecting the use and enjoyment of a water body under any of the following circumstances:

(1) Upon receipt of a request per Env-Wr 702.01;

(2) Upon request of the New Hampshire attorney general; or

(3) On its own motion, when information received by the department warrants further investigation.

(b) The department shall investigate:

(1) The current and past management and control of the outlet; and

(2) The effects, if any, of such management and control on:

a. The use and enjoyment of shore property above the outlet;

b. Any riparian rights below the outlet; and

c. The use and enjoyment of the waters above and below the outlet by the public and by owners of littoral or riparian property.

(c) Based upon the preliminary investigation, the department shall determine whether the management and control of the outlet is having a serious and adverse effect on any of the factors identified in (b)(2), above.

(d) For purposes of the determination in (c), above, a “serious and adverse effect” means an impact that has a reasonable likelihood of interfering with the use and enjoyment of littoral or riparian property or public waters by:

(1) Eroding shorelines above or below the outlet;

(2) Flowing property that is not covered by a flowage easement;

(3) Interfering with access to the waters above or below the outlet;

(4) Causing the waters above or below the outlet to be unsuitable for navigation or recreation;

(5) Causing harm to aquatic or land-based habitat; or

(6) Any combination of (1) through (5), above.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.02); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 703 FURTHER INVESTIGATIONS; PUBLIC HEARING

Env-Wr 703.01 Further Investigation and Public Hearing.

(a) If the department finds a serious and adverse effect under Env-Wr 702.02(c) and (d), the department shall conduct a further investigation.

(b) If the department determines that a public hearing to receive information would be helpful to its further investigation, the department shall schedule and conduct the public hearing in accordance with Env-C 200 relative to non-adjudicative procedures.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.03); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 703.02 Determinations. Based on the further investigation, the department shall:

(a) Ascertain the rights of the owner of the outlet by considering whether:

(1) The dam is registered with the department;

(2) Flowage is within any clear deeded flowage limits;

(3) Base flows are sufficient to accommodate downstream riparian rights;

(4) The operation is in accordance with any deeded rights associated with the former mill dam act, RSA 482:17 through RSA 482:41, if applicable; and

(5) Any other factors that are within the jurisdiction of the department under RSA 482 have been identified by the owner as affecting the rights of the owner;

(b) Ascertain the rights of the public and owners of property above and below the outlet, by considering the following:

(1) Whether there is public access to the impoundment or the stream below the outlet via a government-owned access point;

(2) The extent to which the impoundment or the stream below the outlet is used for fishing, including whether the impoundment is stocked by the New Hampshire fish and game department;

(3) What range of water levels is optimum for the ecological health of the impoundment and the stream below the outlet;

(4) The extent to which the impoundment or the stream below the outlet is used for navigation and what range of water levels is optimum for such navigation;

(5) The extent to which the impoundment or the stream below the outlet is used for swimming and what range of water levels is optimum for swimming; and

(6) The extent to which the impoundment or the stream below the outlet is used for other recreation and range of what water levels is optimum for such other recreation; and

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.03); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

PART Env-Wr 704 FINDINGS; DECISION

Env-Wr 704.01 Findings. After completing its further investigation in accordance with Env-Wr 703, the department shall prepare written findings regarding whether:

(a) The management and control of the outlet is adversely affecting the rights of owners of property above the outlet by eroding shorelines, flowing property not covered by a flowage easement, preventing access to property that is accessible only by boat, or interfering with the use and enjoyment of the water for recreational purposes, including boating, swimming, and fishing;

(b) The management and control of the outlet is adversely affecting the rights of owners of property below the outlet by eroding shorelines, releasing insufficient water for reasonable riparian uses, or interfering with the use and enjoyment of the water for recreational purposes, including boating, swimming, and fishing;

(c) The management and control of the outlet is adversely affecting the rights of the public to use public waters for navigation or recreational purposes, including boating, swimming, and fishing;

(d) The management and control of the outlet is lawful;

(e) The benefits of the current management and control of the outlet outweigh any adverse effects that might be occurring;

(f) Changes to the management and control of the outlet would be of benefit to the public and private interests concerned; and

(g) Changes in the management and control of the outlet to benefit the use and enjoyment of the waters above or below the outlet by the public or by owners of property above or below the outlet would deprive the owner of the outlet or others of rights to which they are lawfully entitled.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.04); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

Env-Wr 704.02 Report of Findings; Decision. Based upon its findings, the department shall:

(a) Order no change in the management and control of the outlet if it finds that:

(1) The benefits of the present management and control of the outlet outweigh any adverse effects on the public and on owners of property above or below the outlet; and

(2) Changes in the management and control of the outlet would not be expected to produce benefits that:

a. Are greater than those resulting from the present management; and

b. Would outweigh any adverse effects of the changes;

(b) Order changes in the management and control of the outlet if the benefits expected from the change are:

(1) Greater than the benefits from the present management and control of the outlet; and

(2) Expected to outweigh any adverse effects of the changed management and control of the outlet;

(c) Report to the governor and council its findings, including an estimate of damages, if it finds that changes in the management and control would be of benefit to the public and private interests concerned but would deprive the owner of the outlet or others of rights to which they are lawfully entitled; or

(d) Report to the attorney general if the management and control of the outlet is unlawful.

Source. #4278, eff 6-30-87; ss by #5662, eff 7-1-93, EXPIRED: 7-1-99

New. #8414, eff 8-20-05 (formerly Env-Wr 401.05); ss by #10510, eff 1-22-14; ss by #13980, eff 5-24-24

CHAPTER Env-Wr 800 ADMINISTRATIVE FINES - EXPIRED

Source. #5082, eff 2-22-91, EXPIRED: 2-22-97; Env-Wr 802.01(e) was amd by #5495, eff 10-27-92, EXPIRED: 10-27-98

CHAPTER Env-Wr 900 OFFICIAL LIST OF PUBLIC WATERS

PART Env-Wr 901 PURPOSE AND APPLICABILITY

Env-Wr 901.01 Purpose. The purpose of these rules is to establish the procedures for the publication and maintenance of the official list of public waters required by RSA 271:20.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 901.02 Applicability. These rules shall apply to the creation and maintenance of the official list of public waters.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

PART Env-Wr 902 DEFINITIONS

Env-Wr 902.01 “Department” means the New Hampshire department of environmental services.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 902.02 “Official list” means the official list of public waters required by RSA 271:20.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 902.03 “Status” means whether a water meets one or more of the categories listed in Env-Wr 903.01 and, if so, which one(s).

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 902.04 “Water” means a surface water body or water course.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

PART Env-Wr 903 CONTENTS AND DETERMINATIONS

Env-Wr 903.01 Waters Listed.

(a) The official list shall include the following:

(1) “Great pond” as defined by RSA 4:40-a, as reprinted in Appendix B;

(2) “Public water” as defined in RSA 215-A:1, as reprinted in Appendix B;

(3) “Public bodies of water” as defined in RSA 233-A:1, as reprinted in Appendix B;

(4) “State-owned public waters” as described in RSA 271:20, I, as reprinted in Appendix B;

(5) “Public waters” as defined in RSA 371:17, as reprinted in Appendix B;

(6) “Public waters” as defined in RSA 482-A:16 and RSA 482-A:21, as reprinted in Appendix B;

(7) “Publicly-owned bodies of water” or “public-owned water bodies” as defined in RSA 482-A:16, as reprinted in Appendix B;

(8) “Public waters” as defined in RSA 483-B:4, XVI, as reprinted in Appendix B;

(9) Public tidal waters as described by the New Hampshire supreme court in Purdie v. Attorney General, 143 N.H. 661 (1999); and

(10) Public rivers or streams as described by the New Hampshire supreme court in St. Regis Paper Co. v. New Hampshire Water Resources Board, 92 N.H. 164 (1942).

(b) The official list shall indicate which statute(s) each listed water is subject to.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 903.02 Determinations. The department shall determine the status of water in New Hampshire based on best available evidence, including the following:

(a) Geographical information system database sets created or maintained by:

(1) The department;

(2) The U.S.D.A. Natural Resources Conservation Service;

(3) The United States Geological Survey (“USGS”);

(4) The United States Environmental Protection Agency;

(5) The complex systems research center of the university of New Hampshire; or

(6) Any combination of the above.

(b) Current and historic USGS topographic mapping;

(d) Historic photographs, including aerial photographs;

(e) Depth contour mapping;

(f) Physical evidence such as shoreline soil, slope and vegetative conditions;

(g) Historical public uses of the water;

(h) Historic documents from the fish and game department;

(i) Historic documents from the department of natural and cultural resources; and

(j) Any other data collected by the department to determine the status of a water.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 903.03 Publication of the Official List.

(a) The department shall make paper copies of the official list available at its offices.

(b) The department shall post the official list at: Official List of Public Waters (nh.gov)

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

PART Env-Wr 904 REVIEW AND REVISION OF THE OFFICIAL LIST

Env-Wr 904.01 Official List Maintenance and Updates.

(a) The department shall maintain the official list to reflect the most accurate information, as listed in Env-Wr 903.02, that becomes available.

(b) The department shall publish each revised official list as specified in Env-Wr 903.03.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13; ss by #13726, eff 8-19-23

Env-Wr 904.02 Initiation of Investigation. The department shall conduct an investigation into the listed status of a water whenever:

(a) It receives conflicting information from credible sources regarding the status of a water; or

(b) When requested by the attorney general.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13 (from Env-Wr 904.01); ss by #13726, eff 8-19-23

Env-Wr 904.03 Posting of Notice.

(a) When the department initiates an investigation pursuant to Env-Wr 904.02, it shall issue a notice that identifies the following:

(1) The name(s) of the water and the town(s) in which the water is located;

(2) The current listed status of the water;

(3) The sources of the conflicting information and a summary of the conflict;

(4) The deadline for submitting factual information for consideration in its decision, which shall be no sooner than 30 days from the date the notice is issued; and

(5) The name, email address, and telephone number of the contact person at the department.

(b) The department shall post on its website and send an electronic copy of the notice to:

(1) The attorney general;

(2) The department of natural and cultural resources;

(3) The fish and game department;

(4) The department of energy;

(5) The department of safety;

(6) The department of transportation; and

(7) The governing body of each community in which the water is located.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13 (from Env-Wr 904.02); ss by #13726, eff 8-19-23

Env-Wr 904.04 Time for Public Comment. Any person may provide factual information pertaining to the status of the water to the department prior to the deadline specified in the notice.

Source. #8383, eff 6-22-05; ss by #10417, eff 9-24-13 (from Env-Wr 904.03); ss by #13726, eff 8-19-23

Env-Wr 904.05 Decision.

(a) The department shall issue a final determination on the status of the water within 180 days of the deadline for submitting factual information established in the notice issued in accordance with Env-Wr 904.03(a).

(b) The department shall send a copy of the decision to all who were sent a copy of the notice pursuant to Env-Wr 904.03(b).

(d) If the decision results in a change to the official list, the department also shall revise the official list by publishing an updated list as specified in Env-Wr 903.03.

Source. #10417, eff 9-24-13 (from Env-Wr 904.04); ss by #13726, eff 8-19-23

Appendix A

Rule Section(s)	State Statute(s) Implemented
Env-Wr 101	RSA 482:1, RSA 482:5; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 102	RSA 482
Env-Wr 103	RSA 482; RSA 91-A:4

Env-Wr 201	RSA 482:6; RSA 482:9, V(a); RSA 482:30; RSA 482:79;
Env-Wr 202	RSA 541-A:22, IV
Env-Wr 203	RSA 482:6; RSA 482:9, V(a); RSA 482:30; RSA 482:79; RSA 541-A:16, I(b)
Env-Wr 204	RSA 541-A:16, I(b)

Env-Wr 301	RSA 482:1; RSA 482:2; RSA 482:87
Env-Wr 302	RSA 482:5; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 303	RSA 482:5; RSA 482:8-a; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 304	RSA 482:5; RSA 482:87

Env-Wr 401	RSA 482:1; RSA 482:7; RSA 482:9 – 11-a; RSA 482:29 – 31; RSA 482:87
Env-Wr 402	RSA 482:1; RSA 482:7; RSA 482:9 – 11-a; RSA 482:29 – 31; RSA 482:87
Env-Wr 403	RSA 482:1; RSA 482:7; RSA 482:9 – 11-a; RSA 482:29 – 31; RSA 482:87
Env-Wr 404	RSA 482:1; RSA 482:7; RSA 482:9 – 11-a; RSA 482:29 – 31; RSA 482:87
Env-Wr 405	RSA 482:1; RSA 482:7; RSA 482:9 – 11-a; RSA 482:29 – 31; RSA 482:87

Env-Wr 501	RSA 482:1; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 502	RSA 482:1; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 503	RSA 482:1; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 504	RSA 482:1; RSA 482:11-a; RSA 482:12; RSA 482:87
Env-Wr 505	RSA 482:1; RSA 482:11-a; RSA 482:12; RSA 482:87

Env-Wr 601	RSA 482:1; RSA 482:2; RSA 482:87
Env-Wr 602	RSA 482:1; RSA 482:2; RSA 482:87
Env-Wr 603	RSA 482:1; RSA 482:2; RSA 482:87
Env-Wr 604	RSA 482:1; RSA 482:2; RSA 482:87

Env-Wr 701	RSA 482:1; RSA 482:4; RSA 482:79-83; RSA 482:87
Env-Wr 702	RSA 482:1; RSA 482:4; RSA 482:79-83; RSA 482:87
Env-Wr 703	RSA 482:1; RSA 482:4; RSA 482:79-83; RSA 482:87

Env-Wr 900	RSA 271:20, II

Appendix B: Incorporation by Reference Information

Rule	Title (Date)	Obtain at:
Env-Wr 303.11(c)(2) Env-Wr 403.03(b)(1)	“Engineering Guidelines for Evaluation of Hydropower Projects”, Chapter 3 (2016) and Chapter 4 (2006)	Federal Energy Regulatory Commission 888 First Street, N.E. Washington, DC 20426 (202)-502-8004 Download at no cost from: https://www.ferc.gov/industries-data/hydropower/dam-safety-and-inspections/eng-guidelines
Env-Wr 303.12(c)(2) Env-Wr 403.03(c)(1)	“Engineering Guidelines for Evaluation of Hydropower Projects”, Chapter 3 (2002) and Chapter 4 (1991)	Federal Energy Regulatory Commission 888 First Street, N.E. Washington, DC 20426 (202)-502-8700 Download at no cost from: http://www.ferc.gov/industries/hydropower/safety/guidelines/eng-guide.asp
Env-Wr 403.04(a)(3) Env-Wr 403.04(a)(4)	Hydrometeorological Report No. 52, Application of Probable Maximum Precipitation Estimates - United States East of the 105th Meridian (1982)	National Oceanic and Atmospheric Administration (NOAA) Hydrometeorological Design Studies Center, W/OHD12 Office of Hydrologic Development National Weather Service/NOAA 1325 East-West Highway Silver Spring, MD 20910-3283 Download at no cost from: https://www.weather.gov/media/owp/hdsc_documents/PMP/HMR52.pdf
Env-Wr 403.05(a)(1)	NRCS “National Engineering Handbook”, Part 630, Hydrology, Chapters 4, 6-10, 14-17, March 2020	UDSA, Natural Resources Conservation Service Download at no cost from: https://directives.nrcs.usda.gov//sites/default/files2/1712930634/Part%20630%20-%20Hydrology.pdf
Env-Wr 403.05(a)(2)	HEC-HMS, version 4.11	U.S. Army Corps of Engineers Hydrologic Engineering Center 609 Second Street Davis, CA 95616 (530) 756-1104 Download at no cost from: https://www.hec.usace.army.mil/software/hec-hms/downloads.aspx
Env-Wr 403.05(a)(3) Env-Wr 502.05(a)	HEC-RAS, version 6.3.1 (2010)	U.S. Army Corps of Engineers Hydrologic Engineering Center 609 Second Street Davis, CA 95616 (530) 756-1104 Download at no cost from: https://www.hec.usace.army.mil/software/hec-ras/download.aspx
Env-Wr 403.05(a)(4)	HydroCAD® Stormwater Modeling, version 10.2	HydroCAD® Stormwater Modeling P.O. Box 477 Chocorua, NH 03817 800-927-7346 Purchase from HydroCAD® Stormwater Modeling ($295) at: https://hydrocad.net/ordering.htm
Env-Wr 403.05(b)(1)	Extreme Precipitation in a Changing Climate for New York and the New England States”, version 2.0	USDA, NRCS and Cornell University’s Northeast Regional Climate Center Access for free at: http://precip.eas.cornell.edu/#/
Env-Wr 403.05(b)(2)	NOAA Atlas 14, Precipitation-Frequency Atlas of the United States”, Volume 10, Version 3.0, 2019	National Oceanic and Atmospheric Administration, National Weather Service Access for free at: https://www.weather.gov/owp/hdsc
Env-Wr 403.05(b)(3)	Hydrometeorological Report No. 51, Probable Maximum Precipitation Estimates, United States East of the 105^th Meridian (1978)	NOAA Hydrometeorological Design Studies Center, W/OHD12 Office of Hydrologic Development National Weather Service/NOAA 1325 East-West Highway Silver Spring, MD 20910-3283 Download at no cost from: https://www.weather.gov/media/owp/hdsc_documents/PMP/HMR51.pdf
Env-Wr 403.05(c)(3)	USDA NRCS National Engineering Handbook, 210-VI-NEH-630.10 (2004)	USDA-Natural Resources Conservation Service (NRCS) 451 West Street Amherst, MA 01002-2995 Download at no cost from: http://directives.sc.egov.usda.gov/viewerFS.aspx?hid=21422
Env-Wr 403.05(c)(9)(b.)	USDA/NRCS Web Soil Survey	USDA Natural Resources Conservation Service Access for free at: https://websoilsurvey.nrcs.usda.gov/app/
Env-Wr 403.06(a)	“Handbook of Hydraulics”, Eighth Edition, (2017)	McGraw-Hill Education 860 Taylor Station Road Blacklick, OH 43004 (877) 833-5524 Purchase for $213 at: https://www.mhprofessional.com/handbook-of-hydraulics-eighth-edition-9781259859687-usa
Env-Wr 403.06(b)(1)	“National Engineering Handbook, Section 5, Hydraulics” (1956)	Download at no cost from: http://directives.sc.egov.usda.gov/viewerFS.aspx?hid=21435
Env-Wr 403.06(b)(2)	“Handbook of Hydraulics”, Seventh Edition, (1996)	McGraw-Hill Education 860 Taylor Station Road Blacklick, OH 43004 (877) 833-5524 Purchase for $110 at: http://www.mhprofessional.com/product.php?isbn=0070072477
Env-Wr 403.07(a)(1)	ACI 318-19(22), “Building Code Requirements for Structural Concrete & Commentary” (2022)	American Concrete Institute 38800 Country Club Dr. Farmington Hills, MI 48331-3439 (248)-848-3800 Purchase ($295 or $175 for members) at: https://www.concrete.org/store/productdetail.aspx?ItemID=318U19&Language=English&Units=US_Units
Env-Wr 403.07(a)(2)	ACI 350-20 and ACI 350R-20: “Code Requirements for Environmental Engineering Concrete Structures and Commentary” (2020)	American Concrete Institute 38800 Country Club Dr. Farmington Hills, MI 48331-3439 (248)-848-3800 Purchase ($215 or $129 for members) at: https://www.concrete.org/store/productdetail.aspx?ItemID=35020&Language=English&Units=US_Units
Env-Wr 403.07(b)(1)	ACI 318-05, “Building Code Requirements for Structural Concrete & Commentary” (2005)	American Concrete Institute 38800 Country Club Dr. Farmington Hills, MI 48331-3439 (248)-848-3700 Purchase from Portland Cement Association ($65) at: http://www.cement.org/bookstore/profile.asp?id=8665
Env-Wr 403.07(b)(2) Env-Wr 403.10(b)(2)	“Design of Small Dams”, Third Edition (1987)	U.S. Department of Interior, Bureau of Reclamation 1849 C Street NW Washington DC 20240-0001 202-513-0501 Download at no cost from: http://www.usbr.gov/pmts/hydraulics_lab/pubs/manuals/SmallDams.pdf
Env-Wr 403.07(b)(3) Env-Wr 403.08(b)(2) Env-Wr 403.09(b)(2)	“National Engineering Handbook, Section 6, Structural Design” (1980)	USDA-NRCS 451 West Street Amherst, MA 01002-2995 Download at no cost from: http://directives.sc.egov.usda.gov/viewerFS.aspx?id=3882
Env-Wr 403.08(a)	“Steel Construction Manual”, Fifteenth Edition (2017)	American Institute of Steel Construction 130 East Randolph, Suite 2000 Chicago, IL 60601-1802 (800) 644-2400 Purchase ($500 or $250 for members) from: https://www.aisc.org/publications/steel-construction-manual-resources/15th-ed-steel-construction-manual/
Env-Wr 403.08(b)(1)	“Steel Construction Manual”, Fourteenth Edition (2011)	American Institute of Steel Construction One East Wacker Drive Suite 700 Chicago, IL 60601-1802 (312) 670-2400 Purchase ($350 for non-members, $175 for members) from http://www.aisc.org/store/p-1578-steel-construction-manual-14th-ed-third-printing-hardbound.aspx
Env-Wr 403.09(a)	“Timber Construction Manual”, Sixth Edition (2012)	American Institute of Timber Construction 7012 S. Revere Parkway, Suite 140 Englewood, CO 80112 (303) 792-9559 Purchase ($146.95) from: https://www.wiley.com/en-us/Timber+Construction+Manual%2C+6th+Edition-p-9780470545096
Env-Wr 403.09(a)	“2018 National Design Specification for Wood Construction” (2018)	American Wood Council 222 Catoctin Cir SE Suite 201 Leesburg, VA 20175 (202) 463-2766 Purchase ($130) from: https://www.abdi-ecommerce10.com/AWC/p-405-2018-nds-electronic.aspx
Env-Wr 403.09(b)(1)	“Timber Construction Manual”, Fourth Edition (1994)	American Institute of Timber Construction 7012 S. Revere Parkway, Suite 140 Englewood, CO 80112 (303) 792-9559 Purchase ($75) from: http://www.amazon.com/Timber-Construction-Manual-Fourth-Edition/dp/B004STZFMW
Env-Wr 403.10(a)	Earth Dams and Reservoirs Technical Release, T.R. 210-60 (2019)	USDA, NRCS 1400 Independence Av., SW Washington, DC 20250 (202) 720-2791 Download at no cost from: https://directives.nrcs.usda.gov/sites/default/files2/1712940996/28860.pdf
Env-Wr 403.10(b)	“Evaluation and Monitoring of Seepage and Internal Erosion” FEMA P-1032, May 2015	Federal Emergency Management Agency Download at no cost from: https://www.fema.gov/sites/default/files/2020-08/fema_p1032_eval_monitoring_seepage_internal_erosion.pdf
Env-Wr 403.10(b)(1)	Earth Dams and Reservoirs, T.R. 60 (2005)	USDA, NRCS 451 West Street Amherst, MA 01002-2995 Download at no cost from: http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044542.pdf
Env-Wr 403.10(b)(3)	ACER Technical Memorandum No. 9, “Guidelines for Controlling Seepage Along Conduits Through Embankments” (1987)	N.H. Dept. of Environmental Services Public Information Center 29 Hazen Drive Concord NH 03301 603-271-3503 Download at no cost from: http://des.nh.gov/organization/divisions/water/dam/documents/rule_ref_book.pdf
Env-Wr 403.10(b)(4)	Agricultural Handbook 590, Ponds – Planning, Design and Construction (1997)	USDA, NRCS 451 West Street Amherst, MA 01002-2995 Download at no cost from: http://usda.mannlib.cornell.edu/usda/nass/general/ah/ah590.pdf
Env-Wr 403.10(c)	“Filters for Embankment Dams – Best Practices for Design and Construction” FEMA, October 2011	Federal Emergency Management Agency Download at no cost from: https://www.fema.gov/sites/default/files/2020-08/filters_embankment_dams_update.pdf
Env-Wr 403.10(d)	“Technical Manual: Conduits through Embankment Dams” FEMA L-266, September 2005	Federal Emergency Management Agency Download at no cost from: https://www.swc.nd.gov/pdfs/conduits_embankment_dams.pdf
Env-Wr 403.10(e)	“Technical Manual: Overtopping Protection for Dams” FEMA P-1015, May 2014	Federal Emergency Management Agency Download at no cost from: https://www.fema.gov/emergency-managers/risk-management/dam-safety/publications
Env-Wr 403.10(f)	“Technical Manual: Plastic Pipe Used in Embankment Dams” FEMA P-675, November 2007	Federal Emergency Management Agency Download at no cost from: https://www.fema.gov/sites/default/files/2020-08/femap_675.pdf
Env-Wr 403.10(g)	NRCS “National Engineering Handbook”, Part 628, Articulated Concrete Block Armored Spillways, Chapter 54, March 2019	UDSA, Natural Resources Conservation Service Download at no cost from: https://directives.nrcs.usda.gov//sites/default/files2/1712930580/Part%20628%20-%20Dams.pdf
Env-Wr 502.07(a)(1)a	Technical Release T.R. 66 “Simplified Dam Breach Routing Procedures” (1985)	USDA, NRCS 451 West Street Amherst, MA 01002-2995 Download at no cost from: http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/national/water/manage/hydrology/?cid=stelprdb1042922
Env-Wr 502.07(a)(1)b	Computer Program for Project Formulation Hydrology, T.R. 20 (1992)
Env-Wr 502.07(a)(1)c	WSP 2 Computer Program, T.R. 61 (1993)
Env-Wr 502.07(a)(2)	National Weather Service Dam-Break Flood Forecasting Model (1987)	NOAA, National Weather Service Office of Hydrologic Development 1325 East West Highway Silver Spring MD 20910 Download at no cost from: http://www.nws.noaa.gov/oh/hrl/hsmb/docs/hydraulics/papers_before_2009/hl_149.pdf
Env-Wr 502.07(a)(3)	HEC-RAS, version 4.1 (2010)	U.S. Army Corps of Engineers Institute for Water Resources Hydrologic Engineering Center 609 Second Street Davis, CA 95616 (530) 756-1104 Download at no cost from: http://www.hec.usace.army.mil/software/hec-ras/

Appendix C: Statutory Definitions

RSA 4:40-a

The governor and council, upon petition and upon recommendation of the department of environmental services, and after consultation with the fish and game commission and such other state agencies as may be involved, may, for such consideration as they deem just, convey sand and gravel which is on the bed of any navigable water or great pond, in accordance with the provisions of this subdivision. For the purposes of this section great pond is defined as a public water of more than 10 acres.

RSA 215-A:1

XI. " Public water " means any public body of water as defined by RSA 271:20 which has been frozen over and is sufficient to hold any person or vehicle, whatsoever. Such public waters shall be deemed a public way and any violation shall be treated as if it took place on land.

RSA 216-I:1

II. “Campsite” means a parcel of land in a recreational campground or camping park rented for the placement of a tent, recreational vehicle, or a recreational camping cabin for the overnight use of its occupants.

RSA 233-A:1

V. "Public bodies of water'' means public waters as defined in RSA 271:20 and any impoundment of a stream, lake, pond, or tidal or marine waters of 10 acres or more, or any other body of water owned by the state or by a state agency or department.

RSA 271:20, I

I. All natural bodies of fresh water situated entirely in the state having an area of 10 acres or more are state-owned public waters, and are held in trust by the state for public use; and no corporation or individual shall have or exercise in any such body of water any rights or privileges not common to all citizens of this state; provided, however, the state retains its existing jurisdiction over those bodies of water located on the borders of the state over which it has exercised such jurisdiction.

RSA 371:17

Whenever it is necessary, in order to meet the reasonable requirements of service to the public, that any public utility should construct a pipeline, cable, or conduit, or a line of poles or towers and wires and fixtures thereon, over, under or across any of the public waters of this state, or over, under or across any of the land owned by this state, modify a previously licensed installation, or license a previously constructed installation, it shall apply to the department of energy for a license to construct and maintain the same. For the purposes of this section, "public waters" are defined to be all ponds of more than 10 acres, tidewater bodies, and such streams or portions thereof as the department of energy may prescribe. Every corporation and individual desiring to cross any public water or land for any purpose herein defined shall apply to the department of energy for a license in the same manner prescribed for a public utility. The department of energy may condition any license issued under this paragraph in any manner necessary to assure that the license may be exercised without substantially affecting the public rights in public waters or state-owned lands. Using a non-adjudicative process, the department of energy may reject incomplete or improperly filed applications, and shall, also using non-adjudicative process, issue or deny the license within 90 days of receiving a complete application and all information subsequently requested of an applicant.

RSA 482:2

I. “Classification of a dam” means the potential hazard classification placed on a dam by the department based on the potential threat to life and the potential extent of property damage in the event of accidental damage to, or failure of, the dam structure. The classifications shall be “non-menace,” “low hazard potential,” “significant hazard potential,” or “high hazard potential.”

II. (a) “Dam” means any artificial barrier, including appurtenant works, which impounds or diverts water and which has a height of 6 feet or more, or is located at the outlet of a great pond. A roadway culvert shall not be considered a dam if its invert is at the natural bed of the water course, it has adequate discharge capacity, and it does not impound water under normal circumstances. Artificial barriers which create surface impoundments for liquid industrial or liquid commercial wastes, septage, or sewage, regardless of height or storage capacity, shall be considered dams.

(b) An artificial barrier at a storm water detention basin, which impounds 0.5 acre-foot or less of water during normal conditions, shall not be considered a dam unless its height is 10 feet or greater or its maximum storage is 6 acre-feet or greater.

V. “Dam in disrepair” means a dam which is a menace to public safety and is incapable of safely impounding flood waters to its crest, or is incapable of maintaining a reasonably constant level of waters impounded, or is one which does not contain adequate gates and sluiceways to provide for the holding or controlled discharge of waters impounded.

VI. “Emergency action plan” means a written document delineating a prescribed sequence of actions to be taken by a dam owner to inform the authorities and others downstream of an impending or actual sudden release of water caused by an accident to, or failure of, the dam. This plan shall be developed in consultation with local officials and notification of the plan shall be given to the general public who would be affected by a sudden release of water caused by an accident or other failure of the dam. The plan shall be kept on file with the local emergency management director and other local officials as deemed appropriate by the department.

VII. “Mills” shall include both manufacturing plants and plants at which electric power is generated for public distribution or for the operation of mills, railroads or public utilities.

VIII. “Person” means any individual, partnership, association, corporation, company, organization or legal entity of any kind.

X. “Reconstruction” means:

(a) A change in the height, length, or discharge capacity of the structure;

(b) Restoring a breached dam or one in ruins;

(c) Modification of flashboards which either increases their height or increases the headwater elevation at which the flashboards will fail; or

(d) A change in the structural configuration of a dam.

RSA 482:13 Public Informational Meeting Required. –

I. No owner shall breach any dam, lower any water body for the repair of any dam, or cause any significant lowering of the water level in a pond or lake without first notifying the local governing body in the cities or towns where said dam or water body is located and the department at least 30 days prior to any action specified above. The provisions of this section shall not apply to dams impounding bodies of water less than 10 acres or to the normal scheduled lowering of water levels each fall, the normal lowering of a water body by the exercise of water rights, the lowering of water levels by the department of environmental services to protect instream flows under RSA 483:9-c, or the lowering of water levels in any emergency situation.

II. The dam owner, in cooperation with the local governing body of each of the cities or towns, shall hold a public informational meeting at least 15 days prior to any action under paragraph I. The dam owner shall publish a notice of the public informational meeting in a newspaper of general circulation in the county in which the action shall occur at least 7 days before the time set for said meeting. The public notice and informational meeting required by this section shall be in addition to and not in place of other provisions of law pertaining to dams.

RSA 482-A:16

No person shall place or cause to be placed any fill in any area below the mean high water level of any public waters or below the artificially-created high water level of publicly-owned bodies of water in this state with the intent or with the effect of creating or forming filled land adjacent to such bodies of water, except as provided in this subdivision. For the purposes of this subdivision, "public waters" means all natural ponds of more than 10 acres, and "publicly-owned bodies of water" or "public-owned water bodies" means those bodies of water whose artificial high water level is maintained by the state's exercise of its flowage rights on these ponds. The provisions of this subdivision shall not apply to such minor improvements of shorelines as the department, by rules adopted by the commissioner under RSA 541-A, may allow.

RSA 482-A:21

I. No person shall excavate, remove, or dredge any bank, flat, marsh, swamp, or lake bed that lies below the natural mean high water level of any public waters of this state, except as provided in this subdivision. For the purposes of this subdivision, "public waters" are defined as all natural ponds of more than 10 acres. Upon the request of the owner of land abutting any public waters, the division shall determine the natural mean high water level of the abutting public water.

II. The provisions of this subdivision shall not apply to:

(a) Any land above the natural mean high water level of public waters.

(b) Any land below any artificially created high water level of any body of water.

(c) Projects classified as minor or minimum impact under rules adopted by the commissioner under RSA 482-A:11 which exclusively involve excavation or dredging within a great pond, and no other associated major project activities requiring a permit pursuant to RSA 482-A.

RSA 483-B:4, XVI

XVI. "Public waters'' shall include:

(a) All lakes, ponds, and artificial impoundments greater than 10 acres in size.

(b) Coastal waters, being all waters subject to the ebb and flow of the tide, including the Great Bay Estuary and the associated tidal rivers.

(c) Rivers, meaning all year-round flowing waters of fourth order or higher and all rivers and river segments designated as protected under RSA 483:15. Stream order shall be determined using the New Hampshire hydrography dataset archived by the geographically referenced analysis and information transfer system (GRANIT) at the complex systems research center of the university of New Hampshire, and developed by GRANIT in collaboration with the department of environmental services. A listing of the streams of fourth order and higher shall be prepared and periodically updated by the GRANIT at the complex systems research center of the university of New Hampshire and delivered to the commissioner 30 days after the effective date of this subparagraph.