Kentucky Administrative Regulations › Title 405 - ENERGY AND ENVIRONMENT CABINET - DEPARTMENT FOR NATURAL RESOURCES › Chapter 18 - Performance Standards for Underground Mining Activities › Section 405 KAR 18:080 - Diversions

Current through Register Vol. 51, No. 1, July 1, 2024
RELATES TO:
				KRS
				350.085,
				350.100,
				350.151,
				350.405,
				350.420,
				350.465
NECESSITY, FUNCTION, AND CONFORMITY: KRS Chapter 350 in
				pertinent part requires the cabinet to promulgate rules and administrative
				regulations establishing performance standards for protection of people and
				property, land, water and other natural resources, and aesthetic values, during
				underground mining activities and for restoration and reclamation of surface
				areas affected by underground mining activities. This administrative regulation
				sets forth requirements for design and construction of temporary and permanent
				diversions of overland flow, shallow groundwater flow, ephemeral streams, and
				intermittent and perennial streams.
Section
			 1. General Requirements.
(1)
			 Surface flow from mined areas abandoned before May 3, 1978 and any flow from
			 undisturbed or reclaimed areas, after meeting the criteria of
			 405 KAR
			 18:070 and
			 405 KAR
			 18:090 for siltation structure removal, may be
			 diverted around the disturbed area and water treatment facilities by means of
			 temporary or permanent diversions.
(2) Diversions shall not be constructed or
			 operated to divert water into underground mines without the approval of the
			 cabinet under
			 405 KAR
			 18:060, Section 9.
(3) The design, construction, and maintenance
			 of diversion ditches shall insure public health and safety, protect property,
			 be stable, minimize adverse impacts to the hydrologic balance, and prevent
			 additional contributions of suspended solids to stream flow and to run off
			 outside the permit area to the extent possible using the best technology
			 currently available. The following criteria are to be incorporated in the
			 design and construction of a diversion ditch:
(a) Freeboard shall be no less than
			 three-tenths (0.3) foot. Protection shall be provided for transition of flows
			 and for critical areas such as swales and curves. Where the area protected is a
			 critical area as determined by the cabinet, the cabinet may require that the
			 design freeboard be increased.
(b)
			 Excess excavated material not necessary for diversion channel geometry or
			 regrading of the channel shall be disposed of in accordance with
			 405 KAR
			 18:130 and
			 405 KAR
			 18:190.
(c) Topsoil shall be handled in compliance
			 with
			 405 KAR 18:050.
(d) Channel protection shall be used to
			 prevent erosion of the ditch. The following criteria shall be used unless the
			 cabinet specifies otherwise:
1. Except when
			 located in solid rock or when riprap or other nonerodible, nondegradable
			 materials are used, diversion ditches are to be fertilized, seeded, and mulched
			 to comply with the requirements of
			 405 KAR 18:200 after
			 the ditch is constructed.
2. Riprap
			 or other nonerodible, nondegradable materials shall be used when a diversion
			 ditch is not located in solid rock or the design velocity is five (5) feet per
			 second or greater for the peak discharge used in the design of the ditch.
			 Material used shall be free of acid-forming material and toxic-forming material
			 and riprap shall comply with the durability requirements of
			 405 KAR
			 18:130, Section 1(6)(c)2, except that sand and gravel
			 shall not be used.
(e)
			 Side slopes shall be no steeper than 1h:4v for solid rock, 1h:1v for riprap
			 lined, and 2h:1v for grass protected ditches.
(f) Diversion ditch design capacity shall
			 comply with the provisions of this paragraph, except where a larger capacity is
			 required by other administrative regulations of 405 KAR Chapters 7 through 24
			 for specific types of diversions or where a larger capacity is required by the
			 cabinet.
1. The channel of any diversion ditch
			 which diverts run-off around a sediment control structure, water treatment
			 facility, or impoundment, excluding dugout structures, shall be adequate to
			 pass the peak discharge from the design storm for the hydraulic capacity of the
			 sediment control structure, water treatment facility, or impoundment (i.e. if
			 the impoundment is designed to pass the 100 year, twenty-four (24) hour storm
			 event so shall the ditch). This size requirement shall not apply if the
			 hydraulic capacity of the sediment control structure, water treatment facility,
			 or impoundment takes into account the entire area contributing drainage, as
			 though the bypass diversion ditch did not exist.
2. The channel of any diversion ditch which
			 diverts run-off to a sediment control structure or water treatment facility
			 shall be adequate, at a minimum, to pass the peak discharge of a ten (10) year,
			 twenty-four (24) hour storm event.
3. The channel, bank, and flood plain
			 configuration of any diversion ditch, which diverts a perennial or intermittent
			 stream, shall be adequate to pass the peak discharge of a ten (10) year,
			 twenty-four (24) hour storm event for temporary ditches and the 100 year,
			 twenty-four (24) hour event for permanent ditches. However, the capacity of the
			 channel itself shall be equal to or greater than the capacity of the unmodified
			 stream channel immediately upstream and downstream of the diversion.
4. The channel of any other diversion ditch
			 which diverts ephemeral streams or overland flow shall be adequate to pass the
			 peak discharge of the two (2) year, twenty-four (24) hour storm for temporary
			 ditches and the ten (10) year, twenty-four (24) hour storm for permanent
			 ditches.
(4)
			 No diversion shall be located so as to increase the potential for land slides.
			 No diversion shall be constructed on existing land slides, unless approved by
			 the cabinet.
(5) Diversions of
			 perennial streams and intermittent streams shall be designed and certified by a
			 registered professional engineer and after construction shall be inspected and
			 certified by the responsible registered professional engineer as having been
			 constructed in accordance with the approved design plans. The certifications
			 required by this subsection shall be made pursuant to
			 405 KAR
			 7:040, Section 10.
(6) Diversion ditches shall be maintained to
			 pass their respective design storms.
(7)
(a)
			 When no longer needed to achieve the purpose for which they were authorized,
			 all temporary diversions shall be removed and the affected land regraded and
			 revegetated, in accordance with
			 405 KAR 18:050, Sections
			 4 and 5;
			 405 KAR
			 18:190; and
			 405 KAR 18:200. At
			 the time diversions are removed, downstream water treatment facilities
			 previously protected by the diversion shall be modified or removed to prevent
			 overtopping or failure of the facilities. This requirement shall not relieve
			 the permittee from maintenance of a water treatment facility otherwise required
			 under 405 KAR or the permit.
(b)
			 Each ephemeral stream channel affected by surface coal mining and reclamation
			 operations shall be reclaimed or permanently diverted in a channel designed and
			 constructed so as to restore or approximate the premining characteristics of
			 the original stream channel (including natural riparian vegetation) to promote
			 the recovery and enhancement of the aquatic habitats, except for situations in
			 which a reach of a stream channel cannot be restored to such characteristics
			 because of the existence of an excess spoil fill, permanent stream-crossing,
			 permanent impoundment, or coal mine waste disposal area constructed in
			 accordance with
			 405 KAR
			 18:100,
			 405 KAR
			 18:130,
			 405 KAR
			 18:140,
			 405 KAR
			 18:160, and
			 405 KAR 18:230 as
			 applicable.