Laserfiche WebLink
• TERROR CREEK COMPANY <br />PROTECTION OF THE HYDROLOGIC BALANCE <br />DRAINAGE AREAS AND SMALL AREA EXEMPTIONS <br />Sedimentation control for the coal loadout facilities is provided by a <br />sediment pond, dugout pond and sediment fences. Run-off calculations for <br />the facilities were prepared based on the handbook, Procedures for <br />Determining Peak Flows in Colorado, Technical Release No. 55 published <br />by the Soils Conservation Service. The computer program Storm (ver. <br />6.21), which ie based on Technical Release No. 55, was used to develop <br />run-off volumes and peak flows. <br />The dominant soil type in the area is Progresso Loam which has a <br />hydrologic classification of "C" according to the USDA-SCS. Five <br />different cover descriptions were chosen to characterize the run-off from <br />the different drainage areas. The curve numbers for A through D are <br />derived from the SCS handbook, Table 2-2c.- Run-off curve numbers for <br />other agricultural lands. The cover descriptions and corresponding curve <br />numbers are as follows: <br />Cover Description <br />A Lush orchardgrass with over 758 ground cover and lightly or <br />only occasionally grazed. Hydrologic Condition - Good. Curve <br />Number 74. <br />• B Orchardgrass with 50 to 758 ground cover and not heavily <br />grazed. Hydrologic Condition - Fair. Curve Number 79 <br />C Orchardgrass, annual grasses, and weeds with less than 508 <br />ground cover. Hydrologic Condition - Poor. Curve Number 86. <br />D Farmsteads, buildings, lanes, driveways and surrounding lots. <br />Curve Number 82. <br />E Coal loadout facilities, coal stockpiles and coal plated yard <br />areas. Curve Number 85. <br />The sediment pond is located is the southeast corner of the facilities <br />area and contains the run-off from the majority of the area. A dugout <br />pond contains the run-off from the topsoil stockpile #1 area. The run- <br />off from the outslope of the facilities pad and the loadout facility is <br />treated by sediment fences. The Sedimentation Control and Small Area <br />Exemption Map #14 shows the drainage areas. Drainage areas 1 - 7 are <br />contained by the sediment pond. Drainage area B is contained by the <br />dugout pond. Run-off from drainage area 9 is treated by sediment fences. <br />Following is a description of the drainage areas. <br />Area 1 <br />Area 1 is the field above the office and bathhouse area. This field <br />encompasses 1.2 acres. The vegetation on the field is a lush stand of <br />• orchardgrass, cover description "A". This area is difficult to walk <br />-1- b/03/93 <br />