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TECHNICAL REVISION 34 <br />DESIGN OF PERMANENT DIVERSION STRUCTURES <br />CHIMNEY ROCK MINE (PERMIT NO. C-81-023) <br />Reclamation of distwbed areas at the Chimney Rock Mine has been ongoing since 1983. As the <br />reclamation matures, there is a need to accommodate drainage from precipitation events. This Technical <br />Revision provides the typical design of pemranent diversion structures that will be installed in the <br />identified drainage ways in accordance with Rules 2.05.3(4) and 4.05.3 and will effectively handle <br />movement of water from the site. These will be permanent structures that will not require maintenance and <br />will remain in place following final bond release. <br />A survey of the reclaimed area was conducted on October 22, 2004 to identify and itventory the drainage <br />ways where permanent diversions will be installed. The inventory identified eleven locations where <br />diversion structures are required (see Drainage Control Map, Map 8). The drainage ways averaged 15 <br />inches deep and 24 inches wide. Length of the drainage ways ranges from 40 to 175 feet with an average <br />of 101 feet. Total azea occupied by the diversions is calculated to be approximately 0.1 acres. Natural <br />rock armor, as well as some vegetative cover, exists in the channels providing stability to the diversions. <br />Head cuts formed by concentration of drainage water will be armored with durable angular rock to ensure <br />long-term stability of the diversions. <br />Installation of the diversions will require minimal disturbance. Head eut locations will be amrored with <br />rock and no seeding or revegetation will be necessary. Angular rocks will be placed with a track dozer and <br />fitted into the slope widr rake and shovel by hand. Specifications for the permanent diversion design are <br />presented on Figure 1. <br />Revised 10/26104 <br />~}P~or¢~ t/~/z~a¢ <br />r R -3¢ <br />