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overbank flow is ~uced during the 100-year •ood and that any erosion will be contained on the property. The slope of the lake's southern bank should be maintained as flat as possible to help control erosion; planting with suitable ground cover is recommAnded. Existing dikes including the - '~e along the southern boundary and along the west bank of the South Platte River must be maintained at their present levels to avoid any change in flood levels, or in the channel-overbank flood relation. If the dikes were to be construct~:d higher, channel flood levels and velocities would increase. If the dikes were lowered, more overbank flooding would occur. If ore continuous lake surface is maintained south of Henderson Road, it is recomrnendec~ ' ~+at peninsulas which extend into the lake be construct.. at a maximum height of 3 feet (elevation a}~pror.imately 5010 feet) above the lake's ultimate surface, This o:ill help control erosion during floods. More than one lake level can be maintained if peninsulas are extended to connect with the opposite side. In this case, peninsulas can be constructed higher, but care should be taken ro design them to withstand overtopping and erosion during flooding. Excavation of the north area is not expected to alter either the flood plain or floodway limit. The slope of the southwest bank of the north lake should be maintained as flat as possible to minimize erosion; ply .:ing with vege- tati~n is considere3 desirable. No buildings for permanent occupation should be allowed caithin the flood plain limits. Temporary ~~ildings and other strictures should be alignod so that their longitudinal axes are parellel to the direction of flow, roughly northeast. The flood plair. regulation.; oL- Adams County should be followed. Planting of trees during reclamation should be done in a manner which iea:;t obstructs the flow, along the east and west banks. Dense planting of trees ~.~uld not be allowed on the peninsulas although isolated plantings can be tolerated without seriously affecting flooding characteristics. Site Drainage During min_ng and reclamation, areas south of i:end~ ion Road will begi,i to drain to the lake formed by the exca- vation. As excavation ~n this area nears Henderson Road, an overflow device shoul3 be constructed which will allow the lake to overflow to the existing culvert under !te^~ on Road. :]orth of Henderson Road, some excavation and cleanout may be required to ensure that the Swale extending from the culvert to IIrantner Gulclt drains adequately. No overflow structure is necessary for the northern lake. The t~•ro existing 1~ ter,:l;: from IIrantner Ditch whit,. serve the area south of Henderson Road will be maintained. -30-