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MINE SITE DRAINAGE FACILITIES TWIN PINES COAL SALES - At the Coal Sales Site the South Oak Creek channel was damaged by the flood. Rip rap recently placed on the south Gank of the channel is gone and slopes have been eroded on both sides of the channel. The concrete ford, recently installed by the Division, was unC ermined on the downstream end. The extent of the Carnage is not know at this time. Large granite boulders were placed by the flood in the creek bed at the road crossing. It appears that large amounts of alluvium have been deposited in the channel up =_tream of the ford. The stream did over flow onto the Coal Sales Site uo stream of the coal stockpile area ar~d flowed between the berm created by recent channel work and the stockpile area to the low area behind the office trailer where it ponded then flowed through the 12 inch culvert to the sediment pond. The sediment pond filled to acoroxi~na tely 1 foot abode the emergency spillway. Wate,- ponded behind the inlet culvert to the pond and behind the scale house. I have not estimated the amount of water going to the pond from the overflow of South Oak Creek. No other appar e~nt damage was noted in the Sales Vard. Drainaoe facilities aooeared to function properly. TWIN PINES MINE SITE - Othe,- than the =_tage of South Oak Creek. the Mine Site appeared to receive more rain roll than the Sales Site. P.un-off Down the slopes abo•~e the County Access Road produced large amounts mud in the road making the site inaccessible fer several hours. At the site the drainage for the most part was directed throuch the sediment ponds with some minor damage due to material wa=_hed down slopes blockino Cra3nage paths. Larne amounts of material washed down the slopes above the high wall forcing some water aver the berm and Co~~,n the sigoe to the pond. The wel! vc-getated =_lopes ore•:er,teC major erosion or the slopes. Cn t;-,e read to the North Spoil Area material .va=_hed f: om the siooe=_ filled the ditch *_o the sediment po rid which resulted in ponding and over flow of the roadside berm. The North Spoil Area was sloped away from the hioh wall which resulted in erosion which filled the aao between the toe dike and the spoil pile and resulted in some overflow dawn the slope. The acce==-s road from Lewis Gulch to the Mine Site held uo well to the storm. The road side ditch will require some work due to erosion fr o~n the storm. Hot`., sediment ponds tilled to a level abo~~~e the overflow. The upper pond filled to ..2 feet abo•~e the lid of the outlet cul•~ert. T. he lower pond fill to about ~i.2 feet above the lip of th.e cul~:•e~-t. Water ponded behind the 24" cmp inlet to the upoer pond *.c a level when= it spiked into the mine. Considerable sediment. mostly rpac base. was evident in the lower pond. Probing ~n the upper pond indicated a sediment level approximate-!y ? ft, below the low Le~:el outlet. Probably the most critical problem esultii~g from she storm is the o1C strip mine spoil slope that oartiaily Clocked Lewis Gulch. A considerable amount of water ponded behind the fell and w entually washed :t out at some t:;ne during the storm. This leaves a quite steep =_looe with no tee. 4la ter did ^pnd above the tee or the 60 inch culvert under t;,e Lewis Gulch Pill.