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weepholes will be used as the principal spillway. Figure 1 shows an example of the inlet and <br />control valve that will be used. The valve is located at the end of the pipe inlet and is controlled <br />by a wheel on the pond embankment. The pipe inlet, or weephole, is kept open enough to <br />facilitate pit pumping discharge, and can be opened further to facilitate discharge after a storm <br />event. <br />Figure 1 - Example of principal spillway inlet and control valve <br />Both the emergency and principal spillway discharge pipes will be buried for a length of roughly <br />300 feet going north from Pond NHN-002. These pipes will then daylight onto the surface, <br />continue around the knob of the mesa to the east, before turning north and proceeding downhill <br />to the final discharge point. At this final discharge point an erosion control "skirt" will be built. It <br />will consist of a plastic liner on the ground with 12 inch plus rock placed on it. The liner will <br />protect the underlying ground from erosion, while the rocks will disrupt and distribute the flow <br />coming out of the pipe. This will allow the discharge to enter Meehan Draw at a lower energy, <br />protecting against erosion. In accordance with Rule 4.05.18, the discharge structures for Pond <br />NHN-002 will not be within the 100 foot buffer zone for Meehan Draw as shown on Map <br />2.05.3(4)-9. The route of the discharge pipes can be seen on Map 2.05.3(4)-9. Portions of the <br />pipe and skirt that are laid on the surface will likely require securing to the ground with stakes or <br />other techniques that will be determined by the contractor in the field. During construction, <br />temporary sediment control will be in place around all construction areas. <br />Appendix 2.05.3(4)-8 Page 2 April 2016 (PR -01) <br />