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Brantner Ditch wat~ will be conveyed to the ~thern lake; some provision must be made at the lake i:o accept it with- out serious erosion. DRAINAGE AFTER RECLAMATION Flood Plain The flood plain and floodway limits will be modified during the mining process as described in the previous section. Final flood plain and floodway limits are shown on Plates I, II, and III. Other modifications will result from other lake configurations. Changes in flood plain and floodway limits will not ext nd upstream or downstream... of the project area. Additional flood storage may be created at the lake sites due to the excavation during the mining process. Increased flood storage will tend to decrease flood peaks for downstream reaches. Additional flood storage can be created if the sr.~uth lake is sectioned off to create multiple water levels as descr wed earlier. IWwever, unless the project is designed specifically with flood .,forage in mind, attain- able flood storage will not have a measureable effect on the 100-year flood peak. Site Drainage Most of the mining site south of Henderson Road will drain directly to the lake. The small over-flow structure at the north end of the lake wi~l be provided although lake overflow will occur only during periods of high runoff. A small portion of the area north of fenderson Road will drain directly to the lake. No outlet for the north iuke is re- quired. SUMMAP.Y The mining and reclamation operation as planned will change the flood plain and floodway limits within the pro- ject area. These changes are identified on Plates I, II, and III. Flood depths velocities and rates of flow will not be changed either upstream or downstrea~* The overbank porti~~n of the 100-year flood will be allowed to pass with- out increasing the damage potential of existing facilities. A11 new facilities will bo designed to minimize ~' d damage. -31