SFPUC 2001 Alameda Watershed Management Plan

XII. SUMMARY OF COMMMENTS AND RESPONSESB. SUMMARY OF COMMENTS AND RESPONSESSunol Valley. However, groundwater sampling in the valley has indicated limitedgroundwater below 50 to 60 feet, and the Management Plan would allow forextending mining from 140 to 200 feet. ThusTherefore, at these depths, groundwaterflows should not be affected. On a program level, the expanded pits would not beexpected to affect Alameda Creek flow and the groundwater system, based onstudies conducted to date. However, a comprehensive groundwater andhydrologic study has not been conducted for all of the proposed expandedmining areas south of I-680. Therefore, potentially significant groundwaterimpacts from expansion of mining pits south of I-680, and subsequent impacts toAlameda Creek and associated resources, cannot be ruled out.In addition, therequirement for bentonite cutoff walls in the upper 50 feet of the pits has resulted indiversion of shallow groundwater away from the mining pits. Therefore, on aprogram level, extending the depth of mining would not be expected to significantlyaffect groundwater.The top portion of Table III.D-5 lists those policies and management actions relatedto gravel mining operations that could result in significant water quality impacts,while the bottom portion of the table lists the full range of policies and managementactions that could be required to reduce the potential impacts. Not every actionwould be necessary to mitigate the effects of the associated potential impact-causingmanagement action. Because implementation information is not yet known, the tableindicates a program-level maximum number of measures that could possibly berequired to avoid significant impacts. On a program level, implementation of theseimpact-reducing measures, as described below, would reduce any water qualityimpacts associated with existing or planned mining operations to a less thansignificant level.The Management Plan includes policies and management actions that requirecontinued and expanded water quality control measures for all existing and newmining operations. Watershed Activities Policy WA5 prohibits instream miningand/or development along reservoir shorelines and tributary streams that are locatedwithin primary Watershed lands. Watershed Activities Policy WA32 specifies that areclamation plan be required and adhered to for all existing and any new mineral,sand, and gravel extraction sites, and that the reclamation plan be approved by theSFPUC and other applicable state and local agencies, prior to any new or expandeddevelopment. Watershed Activities Policy WA24 requires that proposeddevelopment involving grading of land include the submittal of a grading plan toSFPUC to retain the existing topography where feasible, minimize grading, andminimize off-site soil loss from erosion. Because the gravel mining operations arelocated within the Alameda Creek drainage area in the secondary Watershed, waterquality protection is directed at fishery resource uses. Wildlife Policy W6 aims tomaintain the integrity of the Watershed creeks to retain their value as riparianecosystems and wildlife corridors. Fire Policy F3 requires all lessees to conduct fireNOP 96.223E: Alameda Watershed Management Plan C&R.47 ESA / 930385