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~~~ I N C O R V O R A T e D removed and replaced with drained, engineered buttress keyways. The bases of the slopes were reconfigured by constructing relatively level benches to contain debris which may accumulate from the upslope portions of the landslides or open space slopes. _ Several mapped landslides within the GHAD were not removed or altered during the mass grading and development of the site. An "as-built" plan was prepared by the __ geotechnical consultants which shows the limits of the landslide repairs, the subdrain locations and outlets, and the approximate limits of the landslides not removed during grading and development. _. The remaining landslides in the GHAD could reactivate in the future. In addition, new landslides could develop. Also, graded cut slopes could result in the destabilization of open space slopes and cause landslides possibly extending into adjacent developed land. Of lesser, but high impact risk is the potential failure of engineered graded slopes within -- the residential subdivision which could affect more than one Lot and/or dwelling. - 2. Erosion and Sedimentation. The GHAD will address erosion and sedimentation in the Covered Area. Hilly terrain open space either in a natural condition or particularly on excavated slopes can be subject to erosion. Landslide deposits, which are sometimes in a loosened condition, are particulazly prone to erosion. Earth flow-, debris flow- and mud flow-type landslides -- typically have azeas of deposition or accumulation (sedimentation areas) at their bases. Graded slopes in the Covered Area, particularly those in excess of 20 feet in vertical height or those not sufficiently vegetated, can be subject to erosion and, therefore, a source of transported sediment. 4291-W2 July 17, 1997 _ Revised October 9, 1997 Revised October 22, 1997 6