Laserfiche WebLink
Revised April 5, 1985 <br />• Drainage <br />No stream channel crossings presently exist, nor are they planned <br />within the Fish Creek Tipple permit area. <br />No bridges will be constructed and no natural drainage channels will <br />be aitered or relocated within the Fish Creek Tipple Area. All <br />natural drainageways have been crossed using culverts of adequate <br />size, so as not to affect the normal flow or gradient of the drainage. <br />The location and size of culverts are shown on Map 5, Fish Creek <br />Tipple Hydrology and Map 15, Fish Creek Tipple Surface Support <br />Facilities and Structures. Culverts were installed wherever the <br />roadway is a barrier to natural drainage and cross the road at not <br />less than a 30 degree angle. The culverts are covered by a compacted <br />fill to a depth of at least one (1) foot. In locations where surface <br />runoff is away from the haulroad, no culverts are required. Culvert <br />designs are presented in Exhibit 8, Sediment Pond Design. <br />• Rock headwalls or rip-rap have been utilized to protect inlets from <br />erosion. Water flowing through the culvert is discharged below the <br />toe of the fill or into rip-rapped channels and not directly onto any <br />fill material. <br />Inlets and outlets are designed to avoid plugging and collapse. <br />Should trash or debris accumulate, they will be promptly removed. <br />Based upon previous experience in the mine plan area, no special racks <br />or basins are required to protect culvert inlets. Since no culverts <br />have end areas larger than 35 square feet, the design precipitation <br />event is a 10-year, 24-hour event. <br />The haulroad is crowned to prevent ponding and to conduct water into <br />side ditches. Surface runoff from the road is intercepted by <br />diversion ditches and conveyed in a controlled manner, into the <br />natural drainageway. Thereby, drainage from the haulroad will meet <br /> <br />2.05-10 <br />