W. Va. Code R. § 47-34-11

Current through Register Vol. XLI, No. 50, December 13, 2024

Section 47-34-11 - Abandonment of a Dam

11.1. Application to Abandon a Dam - The owner of a dam must obtain a certificate of approval from the Secretary prior to the abandonment of the dam. A complete application in accordance with the provisions of subsection 5.1. must be submitted to and approved by the Secretary prior to the commencement of abandonment activities.

11.2. Reservoir Elimination - The reservoir area shall be completely filled to the crest elevation of the dam with approved material to eliminate the impoundment of water. The maximum impounding capacity upon completion of final grading shall not exceed one (1) acre-foot of impounding capacity. The final top elevation of the reservoir fill shall be higher than, and sloped into, the diversion system required under subsection 11.4.

11.3. Embankment Stability - The remaining embankment shall be shown to achieve a minimum factor of safety in accordance with the provisions of subparagraph 7.4.b.1.D.

11.4. Diversion System - A diversion system designed for a P100 rainfall event shall be provided to capture the stream at the upstream end of the reservoir and convey stream water and embankment runoff water around the site. The diversion system shall outlet safely beyond the downstream toe of the embankment in a natural drainway capable of carrying the design storm without excessive erosion. The Secretary may require the installation of an energy dissipator in accordance with the provisions of subpart 7.4.b.4.B.2.(f).

11.5. Sealing Conduits - All conduits through the embankment, with the exception of underdrain conduits, shall be sealed with concrete at the upstream end prior to elimination of the reservoir. The Secretary may require pressure testing of conduits to determine seal adequacy.

11.6. Erosion and Sediment Control - Erosion and sediment control measures sufficient to comply with the provisions of subdivision 8.1.m. shall be implemented during the abandonment operation.

11.7. Soil and Vegetative Cover - A sufficient layer of topsoil shall be provided to permit long-term growth of vegetation. A seeding and mulching mixture shall be proposed in the abandonment application to accomplish revegetation of the project area.

11.8. Retention of Jurisdiction - The Secretary shall retain jurisdiction over the site for a minimum period of five (5) years after abandonment, during which time the dam and its appurtenances shall be inspected annually by an engineer experienced in such inspections. The inspections shall include measurement readings of instrumentation to determine the level and volume of saturation within the reservoir fill material. The Secretary may also require more frequent reading and reporting of instrument readings to determine seasonal fluctuations of saturation. A report shall be filed with the Secretary detailing the findings of each inspection and describing intended maintenance work. Should a major storm occur, a similar report shall be filed to detail the resultant condition of the structure.

11.9. Final Approval of Abandonment - At the completion of the five-year period, a final joint inspection by the engineer and the Secretary shall be conducted to determine the effectiveness of the abandonment design and the potential need for continued maintenance. Should the Secretary determine as a result of this inspection that an additional inspection time period or maintenance work is required, a letter detailing these requirements shall be sent to the owner. The Secretary will review instrument records and annual inspection reports to determine if the saturation level of material within the reservoir has decreased in volume to less than the legal definition of a "dam." Should the Secretary determine as a result of the inspection and review of instrumentation records that the volume of saturated material is less than the legal definition of a "dam" and the abandonment design has been effective, a letter of acceptance shall be issued stating that the dam has been properly abandoned.

W. Va. Code R. § 47-34-11