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• SURFACE WATER HYDROLOGY <br />The CEC site drainage plan and the associated structures are discussed in Appendix <br />K of the Permit, and can also be found in Technical Revision #28 (2/95), <br />"Drainage Control Plan II". During reclamation, the diversion ditches, drainage <br />ditches, and drainage swales that have been constructed along the roads, and around <br />the north and east sides of the CEC property will serve to convey all surface water <br />runoff to Sediment Pond 2. The present drainage facilities, as well as existing site <br />topographic features, are shown on the Existing Surface Features and Utilities Map <br />(see page 133). Certain surface water control features have been determined to be <br />permanent facilities (by revision, and at the direction of CDMG and others). These <br />features will remain following the completion of all site reclamation activities. The <br />permanent facilities include: <br />• Sediment Pond #2 <br />• The East and the West Perimeter Ditches <br />• The Dugout Pond <br />These permanent drainage features are identified on the Reclamation Contour and <br />Drainage Plan Map (see page 134). <br />• With the exception of Sediment Pond 2 and the Dugout Pond, all previously <br />existing man-made temporary pond sites have been closed, and subsequently <br />deleted from the drainage control mapping and monitoring requirement. This <br />action was considered appropriate because: 1) the sedimentation infill of Sediment <br />Pond 2 has been virtually non-existent after more than fifteen years of continuous <br />use, 2) Sediment Pond 2 has not had significant amounts of water stored in it for <br />more than brief periods (except during the unusual and prolonged periods of excess <br />precipitation in 1995 and 1999), and 3) even considering those unusual events of <br />1995 and 1999, there has never been an observed discharge from Sediment Pond 2. <br />• <br />CEC also implemented a dewatering scheme for Sediment Pond 2 in 1997, in <br />accordance with the revised "Spill Prevention, Control and Countermeasures Plan" <br />for the site. When appropriate, CEC personnel will pump the excess runoff water <br />accumulated in this pond back to the Dugout Pond which is located about 700 feet <br />slightly upgradient and to the south-southeast on CEC property. The Dugout Pond <br />has an available storage capacity exceeding the total contributing runoff volume <br />associated with a 100-year, 24-hour design storm (refer to "Technical Revision <br />Drainage Control Plan II," dated January, 1995). A series of pumps can be <br />employed, as needed, to evacuate the accumulated runoff water in Sediment Pond 2 <br />AHR-2001 -s 8- <br />