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n <br />f. J <br />TABLE 2.05.3(3)7-1 <br />DITCH DESIGN PARAMETERS FOR <br />SMALL AREA EXEMPTION AT TOPSOIL PILE "K" (SAE #1) <br />• <br />• <br />There have been 6 total Small Area Exemptions on the permit area. SAE #2 has been eliminated <br />so that there are 5 SAE's as of the Mid Term Review of 2006. <br />Prior to the mining of the Martin Property, two small area exemptions (SAE) existed property-wide, <br />SAE #1 and #2. SAE #1 consists of about 0.51 acres and is comprised of a small outslope from <br />topsoil pile "K" that is below the grade of.Pond 007. The run-off from this area was modeled using <br />Storm ver6.21. This shows that the total runoff volume is 0.06 acre feet for the 10 year event and <br />the peak flow is 0.65 cfs. This was calculated using a curve number of 95. The topsoil pile has also <br />developed a reasonable vegetation cover over the last 8 years, which means the curve number is <br />approximately 85, resulting in a peak flow which is now far less than the approved amount, further <br />ensuring that effluent limitations are met. <br />(DUE SOUTHWEST OF 007 POND) <br />WATERSHED DATA FOR SMALL AREA EXEMPTION (AREA 3) <br />Curve number <br />Area <br />Hydraulic length <br />Elevation change <br />Concentration time <br />Concentration time type <br />Unit hydrograph type <br />STORM DATA <br />Total precipitation <br />Storm type <br />Peak Discharge <br />Discharge volume <br />REVISED MARCH 2006 <br />Attachment 2.05.3(3)-7-2 <br />95.00 <br />0.50 Acres <br />350.00 Feet <br />7.0 Feet <br />0.07 Hours <br />SCS Upland Curves <br />Disturbed <br />2.0 Inches (10 year-24 hour) <br />SCS Type 2 Storm, 24 hour Storrn <br />0.65 CFS <br />0.06 Acre-ft <br />