BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

significant grading, dredging, or filling to decrease the slope of the finishedapproach to the boat ramp and the boat ramp itself. 80In addition to correct siting, minimize excavation above and below the waterline. An example of such a technique includes the placement of a steel gridfoundation onto piles and cross members, followed by the installation ofprecast concrete sections placed above the grid.The introduction of AIS at LakeTahoe is a serious threat;hence, all boats planning tolaunch within the Lake TahoeBasin should be inspected forAIS and decontaminated atapproved off-site washingstations prior to launching toprevent their introduction intothe lake.Decontamination for AIS is required in the Lake Tahoe Region. The specificprocedures to be followed at any launch facility must be approved by theapplicable regulatory agencies and the Lake Tahoe AIS Program. Currently,the AIS program of roadside washing stations takes precedence. Theintroduction of AIS at Lake Tahoe is a serious threat; hence, all boats planningto launch within the Lake Tahoe Basin should be inspected for AIS anddecontaminated at approved off-site washing stations prior to launching toprevent their introduction into the lake. This program is overseen by the LakeTahoe Aquatic Invasive Species Working Group (LTAISWG) 81 .A pre-cast grease and oil separator or equivalent subsurface stormwatertreatment device must be installed to collect solids, grease, and oils. If aninfiltration facility cannot be accommodated at the wash station due to theproximity of ground water, treated discharges may be collected in a sump andpumped to an off-site facility with adequate infiltration capacity. In the eventan infiltration facility cannot be feasibly constructed or reached, treateddischarges may be pumped to a sanitary sewer provided utility dischargestandards are met and a discharge agreement has been reached with the utilitydistrict. Discharge to a sewer may not always be feasible due to dischargestandards or cost constraints. 82Ramps shall not be greater in width and of the minimum length needed toprovide lake access at normal lake elevations. Single lane ramps can be difficultto use, particularly if they are greater than 100 feet long. If use is up to 50launches and 50 retrievals per day, one lane is sufficient. Boat ramps longerthan 200 feet and less than 60 feet wide should provide a 60-foot minimumdiameter-turning lane.Erosion control features are necessary for all launching ramps to preventundercutting by waves, surge, currents, and runoff drainage. The head of rampshould be not less than 1 foot above legal high water and the toe should be notless than 3 feet below legal low water. A vertical curve at the head of rampmakes the boat ramp easier to use and prevents trailer hitches from hitting the80USACE, 2008, Coastal Engineering Manual - Parts I-681Check http://www.tahoercd.org for the latest information in inspection locations andrequirements.82USACE, 2008, Coastal Engineering Manual - Parts I-6CHAPTER 8: Shorezone Protective Structures and BMPsTRPA BMP Handbook8.12 Boat Ramp Construction and Vehicle Source Control Methods and Design 2012Page 8-80