RES 97128 - Laserfiche WebLink

GI Yt7~ I N C O 4 V O R A T t D Potential landslide and erosion hazards can be reduced by controlling saturation and water runoff through the maintenance of surface and subsurface drainage systems. This includes maintenance of the concrete-lined V-shaped drainage ditches. E. Biotechnical Recommendations for Prevention and Mitigation of Existing or Potential - Erosion Hazards. - ~ Biotechnical slope protection involves the use of mechanical elements or structures in combination with biological elements (plants) to provide erosion control and help prevent small- -- scale slope failures. Locally, crib walls, welded-wire walls, gabion walls, rock walls, riprap, and reinforced earth walls used in combination with carefully-selected and planted vegetation can - provide high quality slope protection. The vegetation may be planted on the slope above a low retaining structure or toe wall, or within the interstices of the. Alternatively, a slope can be ~~ terraced with vegetation planted on the steps. _ Vegetation provides a protective cover on soil and exposed rock. It absorbs the impact of raindrops, reduces the velocity of runoff, and retazds erosion. If seeding is done too early, however, such as before September, seed loss by birds and wind may be significant. Graded slopes on this project may be more erodible than natural. Therefore, maintenance of vegetative cover following grading is especially important. A Landscape Architect should consult with the Project Geotechnical Engineer on this matter. F. Maintenance and Monitoring Schedule. Inspections of the Covered Area should be done at least twice each yeaz. As a prudent measure, the budget reserves will accommodate at least two additional inspections for years of heavy rainfall. The inspections will take place in August (prior to the first significant rainfall) and in 4291-W2 July 17, 1997 _ Revised October 9, 1997 Revised October 22, 1997 1d