SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSD. HYDROLOGY AND WATER QUALITYwere implemented, these activities associated with the Management Plan could cause substantialerosion or siltation, either individually or cumulatively. Therefore, these activities could result inpotentially significant hydrologic impacts to stream channel and flow and to reservoir storagecapacity.While the Management Plan proposes certain management actions that could bring aboutphysical effects, the Management Plan also includes actions that would reduce these potentialeffects. Table III.D-8 is provided to link, at a program level, those actions that could result inpotential impacts (column 1) with the full range of actions that could be required to reduce thepotential impacts (column 2). The table highlights in bold text those actions that may beessential to reduce significant impacts column 1 actions, depending on the specific nature of themanagement action, such as design, siting, or implementation schedule. These essential actions,as well as the other actions (in non-bold text) that would further reduce potential physical effects,are discussed below. The table also indicates the level of impact significance that would remainif the actions discussed were implemented. Not every bolded action would be necessary tomitigate the effects of the associated potential impact-causing management action. For example,a very minor structure such as a kiosk located in an environmentally non-sensitive area may notrequire any of the bolded actions to avoid a significant effect. Because implementationinformation, such as locations of specific facilities, is not yet known, the table indicates aprogram-level maximum number of measures that could possibly be required to avoid significantimpacts. Management actions would be reviewed at the time they are proposed forimplementation to determine the potential for project-specific impacts and to identify appropriatemitigation measures (see Section II.E.5.0, Mitigation Monitoring and Reporting).Policies and management actions presented in the Management Plan would ensure that erosion,sedimentation, and siltation could be controlled within the Watershed and that potentialhydrologic impacts would be mitigated. Policies and management actions that would mitigatesedimentation and erosion impacts include WQ14, WQ15, WQ16, WQ17, WS1, WA24, roa2,roa3, roa4, roa7, roa12, veg4, veg7 aqu6, aqu7, aqu10, aqu11, and aqu12 and the policies andactions associated with the Alameda Watershed Fire Management Element. Policies WQ14,WQ15, WQ16, and WQ17 minimize the number of roads, prohibit activities that have thepotential to cause erosion, establish sediment basins, and minimize the creation of impervioussurfaces. Policy WS1 calls for minimizing sedimentation to reservoirs, and Policy WA24requires grading plans to minimize off-site soil loss from erosion. Actions roa2, roa3, roa4, roa7,and roa12 provide for siting and modifications to roads that would minimize sedimentation anderosion. Actions veg4 and veg7 require grading plans and erosion control practices. Actionsaqu7, aqu10, aqu11, and aqu12 provide for management of stream channels and sedimentationbasins. The 14 fire management actions provide an integrated approach to fire management andthe protection to water quality.On a program-level, implementation of the policies and management actions described above andin Section IV.D, particularly those in bold type, would reduce potential hydrologic impacts to aless than significant level. No unavoidable significant program-level sediment build-up impactshave been identified in this EIR. However, the San Francisco Planning DepartmentNOP 96.223E: Alameda Watershed Management Plan III.D-35 ESA / 930385January 2001