Illinois Administrative Code › Title 62 - MINING › Part 1817 - PERMANENT PROGRAM PERFORMANCE STANDARDS - UNDERGROUND MINING OPERATIONS › Section 1817.43 - Diversions

Current through Register Vol. 48, No. 28, July 12, 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
			 1817.46
			 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
			 1817.41(h).
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 stream flow outside the permit area. Appropriate sediment control
			 measures for diversions may include, but not be limited to, maintenance of
			 appropriate gradients, channel lining, revegetation, roughness structures, and
			 detention basins; and
D) Comply
			 with the Rivers, Lakes, and Streams Act [615 ILCS 5 ], Section 404 of the
			 Federal Water Pollution Control Act of 1972, as amended ( 30 USC 1344 ), and
			 all local ordinances.
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 permittee
			 from maintaining water treatment facilities as otherwise required. When
			 permanent diversions are constructed or stream channels restored prior to the
			 removal of temporary diversions the permittee shall:
A) Establish, restore, enhance where
			 practicable, or maintain natural riparian vegetation on the banks of the
			 stream, including any area that is subject to annual inundation;
B) Establish or restore the stream to its
			 natural meandering shape and to an environmentally acceptable gradient, as
			 determined by the Department; and
C) Establish or restore the stream to a
			 longitudinal profile and cross - section, including aquatic habitats (usually a
			 pattern of riffles, pools, and drops rather than uniform depth) that
			 approximate premining stream channel characteristics.
4) Diversion design shall incorporate the
			 following:
A) Channel lining shall be designed
			 using standard engineering practices to pass safely the design velocities.
			 Riprap shall consist of non-degradable, non-acid or toxic-forming rock such as
			 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,
			 except as provided for in subsection (a)(5). 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 streams 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
			 1817.71
			 through
			 1817.74;
			 and
E) Topsoil shall be handled in
			 compliance with Section
			 1817.22.
5) If the terrain is such that
			 out-of-bank flows can accommodate the design precipitation event without
			 endangering health or the environment as a result of flooding, such as physical
			 harm or slope failure, the need for diversion ditches may be modified by taking
			 into account channels, banks, and flood plains.