Section 90.105. Stream channel diversions

(a) Flow from perennial and intermittent streams within the permit area may be diverted if the diversions:

(1) Will not adversely affect, during and after coal refuse disposal activities, the water quantity and quality of the stream.

(2) Comply with other requirements of this chapter and Chapter 105 (relating to dam safety and waterway management).

(b) When stream flow diversion is approved, the stream channel diversion shall be designed, constructed and removed in accordance with the following:

(1) The longitudinal profile of the stream, the channel and the flood plain shall be designed and constructed to remain stable and to prevent, to the extent possible using the best technology currently available, additional contributions of suspended solids to stream flow or to runoff outside the permit area. These contributions may not be in excess of requirements of State or Federal law. Erosion control structures, such as channel lining structures, retention basins and artificial channel roughness structures shall be approved for permanent diversion only when they are stable and will require infrequent maintenance.

(2) The combination of channel, bank and flood plain configurations shall be adequate to prevent a flooding potential greater than that created by the natural condition of the existing channel. However, the capacity of the channel itself shall be at least equal to the capacity of the unmodified stream channel immediately upstream and downstream from the diversion.

(3) The design and construction of stream channel diversions of perennial and intermittent streams shall be certified by a qualified registered professional engineer as meeting the performance standards of this part.

(c) When no longer needed to achieve the purpose for which they are authorized, temporary stream channel diversions shall be removed and the affected land regraded and revegetated, in accordance with § § 90.150—90.157, 90.159 and 90.160. At the time diversions are removed, treatment facilities previously protected by the diversion shall be modified or moved to prevent damage or failure of the facilities. This requirement does not release the person who conducts the coal refuse disposal activities from maintenance of a water treatment facility otherwise required under this chapter, and the erosion and sedimentation control requirements of § 90.106 (relating to hydrologic balance: erosion and sedimentation control).

(d) When permanent diversions are constructed or stream channels are restored after temporary diversions, the operator shall:

(1) Restore or maintain and enhance, where practicable, natural riparian vegetation of the banks of the stream.

(2) Restore the horizontal alignment of the stream to a condition compatible with the identified protected water use of Chapter 93 (relating to water quality standards).

(3) Restore the stream to a longitudinal profile and cross section, including aquatic habitats, that approximate predisposal stream channel characteristics.

The provisions of this § 90.105 adopted December 19, 1980, 10 Pa.B. 4789, effective July 31, 1982, 12 Pa.B. 2382; amended July 30, 1982, 12 Pa.B. 2473, effective July 31, 1982, 12 Pa.B. 2382; amended June 15, 1990, 20 Pa.B. 3383, effective July 27, 1991, 21 Pa.B. 3316. Immediately preceding text appears at serial pages (149035) to (149037).

Notation

Cross References

This section cited in 25 Pa. Code § 90.36 (relating to stream diversions, water obstructions and encroachments); 25 Pa. Code § 90.113 (relating to hydrologic balance: coal processing waste dams and embankments); and 25 Pa. Code § 90.122 (relating to coal refuse disposal).