Oklahoma Administrative Code › Title 460 - Department of Mines › Chapter 20 - The Permanent Regulations Governing the Coal Reclamation Act of 1979 › Subchapter 43 - Permanent Program Performance Standards: Surface Mining Standards › Section 460:20-43-10 - Diversions

Current through Vol. 41, No. 20, July 1, 2024
(a)
General
				requirements.
(1) With the approval of
				the Department, any flow from mined areas abandoned before May 3, 1978, and any
				flow from undisturbed areas or reclaimed areas, after meeting the criteria of
				Section
				460:20-43-12
				for siltation structure removal, may be diverted from disturbed areas by means
				of temporary or permanent diversions. All diversions shall be designed to
				minimize adverse impacts to the hydrologic balance within the permit and
				adjacent areas, to prevent material damage outside the permit area and to
				assure the safety of the public. Diversions shall not be used to divert water
				into underground mines without approval of the Department under Section
				460:20-43-8(i).
(2) The diversion and its appurtenant
				structures shall be designed, located, constructed, maintained and used to:
(A) Be stable;
(B) Provide protection against flooding and
				resultant damage to life and property;
(C) Prevent, to the extent possible using the
				best technology currently available, additional contributions of suspended
				solids to streamflow outside the permit area; and
(D) Comply with all applicable local, State,
				and Federal laws and regulations.
(3) Temporary diversions shall be removed
				promptly when no longer needed to achieve the purpose for which they were
				authorized. The land disturbed by the removal process shall be restored in
				accordance with this part. Before diversions are removed, downstream
				water-treatment facilities previously protected by the diversion shall be
				modified or removed, as necessary, to prevent overtopping or failure of the
				facilities. This requirement shall not relieve the operator from maintaining
				water-treatment facilities as otherwise required. A permanent diversion or a
				stream channel reclaimed after the removal of a temporary diversion shall be
				designed and constructed so as to restore or approximate the premining
				characteristics of the original stream channel including the natural riparian
				vegetation to promote the recovery and the enhancement of the aquatic
				habitat.
(4) Temporary diversions
				shall be constructed to pass safely the peak runoff from a precipitation event
				with a 2-year, 6-hour recurrence interval or a larger event as specified by the
				Department.
(5) To protect fills
				and property and to avoid danger to public health and safety permanent
				diversions shall be constructed to pass safely the peak runoff from a 6-hour,
				10-year precipitation event or a larger event as specified by the Department.
				Permanent diversions shall be constructed with gently sloping banks that are
				stabilized by vegetation. Asphalt, concrete or other similar linings shall be
				used only when approved by the Department to prevent seepage or to provide
				stability.
(6) Diversions shall be
				designed, constructed and maintained in a manner which prevents additional
				contributions of suspended solids to streamflow and to runoff outside the
				permit area to the extent possible using the best technology currently
				available. Appropriate sediment control measures for these diversions may
				include, but not be limited to maintenance of appropriate gradients, channel
				linings, revegetation, roughness structures, and detention basins.
(7) No diversion shall be located so as to
				increase the potential for landslides. No diversion shall be constructed on
				existing landslides unless approved by the Department.
(8) When no longer needed, each temporary
				diversion shall be removed, and the affected land regraded, topsoiled, and
				revegetated in accordance with these Regulations.
(9) Diversion design shall incorporate the
				following:
(A) channel lining shall be
				designed using standard engineering practices to pass safely the design
				velocities. Riprap shall be nondegradable, nonacid or toxic forming rock such
				as natural sand and gravel, sandstone, limestone, or other durable rock that
				will not slake in water and will be free of coal, clay, or shale.
(B) Freeboard shall be no less than 0.3 feet.
				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 Department, the design freeboard may be increased.
(C) Energy dissipators shall be installed
				when necessary at discharge points. Where diversions intersect with natural
				steams and exit velocity of the diversion ditch flow is greater than that of
				the receiving stream.
(D) Excess
				excavated material not necessary for diversion channel geometry or regrading of
				the channel shall be disposed of in accordance with Sections
				460:20-43-24,
				through
				460:20-43-27.
(E) Topsoil shall be handled in compliance
				with Section
				460:20-43-7.
(F) Diversions shall not be constructed or
				operated to divert water into underground mines without approval of the
				Department.