Md. Code Regs. 26.20.21.04

Current through Register Vol. 51, No. 19, September 20, 2024

Section 26.20.21.04 - Stream Channel Diversions

A. Flow from perennial and intermittent streams within the permit area may be diverted, if the diversions:

(1) Are approved by the Bureau after making a finding that the diversion will not adversely affect the water quantity and quality and related environmental resources of the stream;

(2) Comply with other requirements of this regulation; and

(3) Comply with local, State, and federal statutes and regulations.

B. When streamflow is allowed to be diverted, 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 floodplain shall be designed and constructed to remain stable and, to the extent possible using the best currently available technology, to prevent additional contributions of suspended solids to streamflow 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 used in diversions only when approved by the Bureau as being necessary to control erosion. These structures shall be approved for permanent diversions only where they are stable and will require infrequent maintenance.

(2) The combination of channel, bank, and floodplain configurations shall be adequate to pass safely the peak runoff of a 10-year, 24-hour precipitation event for temporary diversions, a 100-year, 24-hour precipitation event for permanent diversions, or larger events specified by the Bureau. However, the capacity of the channel itself should be at least equal to the capacity of the unmodified stream channel immediately upstream and downstream of the diversion.

(3) The design and construction shall be certified by a qualified professional engineer as meeting the design criteria of the Regulatory Program.

C. When no longer needed to achieve the purpose for which they were authorized, all temporary stream channel diversions shall be removed and the affected land regraded and revegetated. 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 does not relieve the permittee from maintenance of a water treatment facility otherwise required under this chapter or the permit.

D. When permanent diversions are constructed or stream channels restored, after temporary diversions, the operator shall:

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

(2) Establish or restore the stream to its natural meandering shape or an environmentally acceptable gradient, as determined by the Bureau; and

(3) Establish or restore the stream to a longitudinal profile and cross section, including aquatic habitats that approximate pre-mining stream channel characteristics.

Md. Code Regs. 26.20.21.04

Regulations .04 were previously codified as COMAR 08.13.09.24 a A_I, respectively. Recodification occurred in April, 1993. For a history of these regulations before April, 1993, see "Administrative History of COMAR 08.13.09 before April, 1993" which follows COMAR 26.20.01.