Current through Register Vol. XLI, No. 37, September 13, 2024
Section 38-4-21 - Abandonment of a Dam21.1. 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 Section 5.1 of these rules must be submitted to and approved by the Secretary prior to the commencement of abandonment activities.21.2. The reservoir area shall be completely filled to the crest elevation of the dam with approved material to eliminate the impoundment of water. The final top elevation of the embankment must be higher than, and sloped into, the diversion ditch. Maximum slope of the top of the embankment to the diversion ditch shall be five (5) percent unless otherwise approved by the Secretary.21.3. The embankment shall be shown to achieve a minimum long-term factor of safety in accordance with the applicable provisions of Section 11 of these rules.21.4. Diversion System: A diversion system designed to conduct a 100 year 24 hour storm shall be provided to capture the stream at the upstream end of the reservoir and convey stream water and runoff from the surface of embankment around the site. The diversion system shall outlet safely beyond the downstream toe of the embankment in a natural drain way capable of carrying the design storm without excessive erosion.21.5. All conduits through the embankment with the exception of under drain 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.21.6. Erosion and sediment control measures sufficient to comply with the provisions of rules shall be implemented during the abandonment operation.21.7. A sufficient layer of topsoiling material shall be provided to insure a long-term vegetation.21.8. The Secretary shall retain jurisdiction over the site for a minimum period of five years after abandonment, during which time the dam and its appurtenances shall be inspected annually by an engineer experienced in such inspections. 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.21.9. At the completion of five year period, a final joint inspection by the engineer and the Secretary's representative 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. Should the Secretary determine as result of the inspection that the abandonment design has been effective, a letter of acceptance shall be issued stating that the dam has been properly abandoned and the reclamation bond of the permittee shall be released.