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Reso 0908-07/1991RESOLUTION NO. 908 RESOLUTION OF THE BOARD OF DIRECTORS OF THE VALLECITOS WATER DISTRICT CERTIFYING AS COMPLETE AND ADEQUATE ENVIRONMENTAL IMPACT REPORT SCH #90010707 AND ADOPTING CANDIDATE FINDINGS AND STATEMENT OF OVERRIDING CONSIDERATIONS AND NORTH TWIN OAKS RESERVOIR MITIGATION MONITORING PLANS WHEREAS, the Vallecitos Water District ("District") determined that the draft Water, Wastewater, and Reclamation Master Plan may have a significant effect on the environment and required the preparation of an Environmental Impact Report; and WHEREAS, Environmental Impact Report SCH #90010707 provides a full disclosure of the anticipated environmental impacts of the proposed Water, Wastewater, and Reclamation Master Plan, a Proposed Land Outfall and Reclaimed Water Failsafe Pipelines, a Central San Marcos Reclamation Facility, and a North Twin Oaks Reservoir; and WHEREAS, a Draft Environmental Impact Report ("DEIR") was prepared for the said projects pursuant to the provisions of the California Environmental Quality Act, as amended; and WHEREAS, the DEIR was distributed to those public agencies having jurisdiction by law with respect to the project and to other interested persons and agencies for review and comment for a period of 45 days; and WHEREAS, an extension of the comment period was provided to incorporate late responses; and WHEREAS, two public meetings were conducted during the review period to provide an additional forum for public input; and WHEREAS, written comments were received from the responsible agencies and the public; and WHEREAS, the Final Environmental Impact Report ("FEIR") including a comprehensive set of responses to all comments has been prepared; and WHEREAS, the District has reviewed and considered the FEIR prior to acting on the proposed projects and has certified that the FEIR has been completed in compliance with the California Environmental Quality Act ("CEQA") Guidelines; and WHEREAS, the District has determined that the FEIR adequately addresses the impacts of the projects being considered and that mitigation measures have been incorporated into the proposed project which substantially lessen the significant environmental effects of the projects as identified in the FEIR; and Resolution 908 Page Two WHEREAS, evidence was heard from all persons interested in affecting said Final Environmental Impact Report and for all persons protesting; and WHEREAS, the District has reviewed all of the environmental documentation comprising EIR SCH #90010707 and has found that the EIR SCH #90010707 considers all environmental impacts of the proposed projects and is complete and adequate and fully complies with all requirements of CEQA and the CEQA Guidelines; NOW, THEREFORE, BE IT RESOLVED that the Board of Directors of the Vallecitos Water District as follows: SECTION 1: The Board of Directors of the Vallecitos Water District does hereby certify Final EIR SCH #90010707 as complete and adequate in that it addresses all environmental effects of the proposed projects and fully complies with the requirements of the California Environmental Quality Act and the CEQA Guidelines. Said Final EIR SCH #90010707 is composed of the following components: A. Public Review Comments and Responses (A-l) B. Summary (S-1) C. Master Plan Mitigation Monitoring Program (1-3 -- 1-5) D. Vallecitos Master Plan EIR (2-1 -- 2-89) E. Land Outfall and Reclaimed Water Failsafe Line EIR (3-1 -- 3-53) F. Central San Marcos Water Reclamation Facility EIR (4-1 -- 4-68) H. Public Health and Safety Assessments (6-1 -- 6-8) I. Other Master Plan projects (7-1 -- 7-3) J. Growth Inducement (8-1 -- 8-8) K. Cumulative Impacts (9-1 -- 9-14) L. Other Required CEQA Sections (10-1) SECTION 2: The Board of Directors hereby adopts the Candidate Findings and the Statement of Overriding Considerations {attached hereto as Exhibit "A"} and the North Twin Oaks Reservoir Vallecitos Water District Mitigation Monitoring Plan (attached hereto as Exhibit "B"}, both of which are incorporated herein by this reference. Such findings and statements are based upon substantial evidence in the record including Final EIR SCH #90010707. G. North Twin Oaks Reservoir EIR (5-1 -- 5-42) Resolution 908 Page Three SECTION 3: The Board of Directors finds that the mitigation measures described in the Final EIR and subsequent site specific CEQA review should mitigate significant adverse effects of the proposed projects to a level of insignificance. SECTION 4: The Board of Directors finds that the identified, unavoidable, and significant effects of the projects are acceptable due to the adoption of the Statement of Overriding Considerations (attached hereto as Exhibit "A"). Such findings are based upon substantial evidence in the record including Final EIR SCH #90010707. PASSED, APPROVED, AND ADOPTED by the Board of Directors of the Vallecitos Water District this 1st day of July, 1991, by the following roll call vote: AYES: Burton, Ferguson, Gregoryk, Mason, Newport NOES: ABSENT: ABSTAIN: Mary Anr{ ~4ewport, ~re~d~t Boardof~i)i rector~ ~-~/ Vallecitos Water District ATTEST: William W. Rucker, Secretary Board of Directors Vallecitos Water District CANDIDATE FINDINGS AND STATEMENT OF OVERRIDING CONSIDERATIONS Vallecitos Water District Water Wastewater and Reclamation Master Plan SCH No. 90010707 The California Environmental Quality Act (CEQA) requires that no public agency shall approve or carry out a project for which a Final Environmental Impact Report (EIR) identifies one or more significant effects thereof, unless such public agency makes one or more of the following findings: (1) Changes or alterations have been required in, or incorporated into, such project which mitigate or avoid the significant environmental effects thereof as identified in the completed environmental impact report. (2) Such changes or alterations are within the responsibility and jurisdiction of another public agency, and such changes have been adopted by such other agency or can and should be adopted by such other agency. (3) Specific economic, social, or other considerations make infeasible the mitigation measures or project alternatives identified in the environmental impact report. (Section 21081 of the California Environmental Quality Act) CEQA further requires that, where the decision of the public agency allows the occurrence of significant effects which are identified in the Final EIR but are not at least substantially mitigated, the agency shall state in writing the specific reasons to support its action based on the Final EIR and/or other information in the record (Section 15093 of the CEQA Guidelines). - 1- 90-06.099 06/28/91 EXHIBIT A FINDINGS FOR THE VALLECITOS WATER DISTRICT The folloWing findings are made relative to the conclusions and recommendations of the Final EIR for the Vallecitos Water District (VWD) Water, Wastewater hnd Reclamation Master Plan (SCH No. 90010707). These findings have been prepared pursuant to Section 21081 of the California Public Resources Code and Sections 15091 and 15093 of the California Administrative Code. The subject EIR includes individual environmental analyses for the Master Plan (conducted at a program level) and three separate facilities (conducted at a project level). Accordingly, the following discussion of findings includes separate sections for the proposed Master Plan and North Twin Oaks Reservoir (the only specific project proposed for approval). The VWD Board, having reviewed and considered the information contained in the Final EIR and public record, finds that the following changes or alterations are being required, or have been incorporated into the project to mitigate or avoid significant environmental impacts identified in the EIR. A. MASTER PLAN ANALYSIS 1. Land Use Impacts. Proposed Master Plan facilities would be required to conform w/th existing and planned land use designations and zoning. Assuming such compliance is maintained, no significant land use impacts would result. Findings. Site-specific CEQA review would be required for all individual Master Plan facilities. These analyses would include pertinent requirements to ensure compliance with applicable land use designations and zoning. Biolo~ Impacts. Portions of the VWD service area contain sensitive biological resources, including riparian, marsh, sage scrub, and oak woodland -2- 9o-o6. o99o6/28/91 o habitats, as well as several rare floral and faunal species. Implementation of the proposed Master Plan may result in significant impacts to biological resources through construction of facilities such as pipelines and reservoirs. Findings. Construction of individual Master Plan projects will require site-specific CEQA review prior to implementation. Such review would require mitigation of potentially significant biological impacts through measures such as avoidance, onsite restoration, and on- or offsite habitat replacement. Cultural Resources. Impacts. Nearly all portions of the VWD service area subject to development under the Master Plan exhibit some potential for the occurrence of significant cultural resource values. Construction of Master Plan facilities could result in Significant impacts through loss of or damage to such resource values. Findings. Construction of individual Master Plan projects will require site-specific CEQA review prior to implementation. Such review would require mitigation of potentially significant impacts to cultural resources through site investigation and appropriate testing and data recovery. Air Quality and Odors Impacts. Implementation of the proposed Master Plan would result in site-specific and cumulative impacts related to emissions of reactive organic gases and particulate matter from stationary sources (e.g., pump stations). These impacts are considered significant due to the current non-attainment status of the San Diego Air Basin. Findings. Impacts to air quality associated with long-term stationary sources would be subject to reduction through the use of best available -3- oo_o~.ooo o~/28/9 ~ technology to limit total emissions. Because of the described non- attainment status, however, such impacts would not be reduced below a level of significance and are considered unmitigable. Visual Ouality Impacts. Development of proposed Master Plan facilities could potentially result in significant impacts to visual resources from construction of facilities such as reservoirs and pump stations. Findings. Construction of individual Master Plan projects will require site-specific CEQA review prior to implementation. Such reviews would identify measures to mitigate visual impacts, including methods such as landscape screening and the use of appropriate facade colors and textures. Due to the nature and size of certain facilities, however, it is conceivable that significant unmitigable impacts could result. Noise Impacts. Implementation of the Master Plan will result in potentially significant noise impacts related to construction activities and the operation of certain facilities (e.g., pump stations). Findings. Construction of individual Master Plan projects will require site-specific CEQA review prior to implementation. Such reviews would identify measures to reduce noise-related impacts, including appropriate setbacks and restrictions on hours of operation. Depending on the nature and location of individual facilities, however, certain activities (e.g., construction blasting) could result in significant unmitigable impacts. Traffic Circulation Impacts. Potential traffic impacts related to the proposed Master Plan facilities would be limited to short-term construction activities. While -4- 9o.06. o99 06/28/91 such impacts are generally not considered significant, site-specific conditions (e.g., areas of existing unacceptable levels of service) could result in variable impact levels. Findings. Construction of individual Master Plan projects will require site-specific CEQA review prior to implementation. Such reviews would identify measures to mitigate traffic-related impacts, including work restrictions during peak traffic periods. GeoloKy and Soils Impacts. Master Plan facilities have the potential to generate significant impacts and/or be significantly affected by geologic concerns. Specific issues include the loss of Prime Farmland, seismic hazards, soil instability, shallow bedrock and groundwater, and disposal of excess or oversize material. o Findings. Individual Master Plan facilities will require site-specific geotechnical investigation prior to construction. These studies will identify mitigation measures to avoid impacts or reduce them below levels of significance. Hydrology/Water Ouali .ty Impacts. Implementation of the proposed Master Plan could potentially generate significant impacts to hydrologic issues including drainage alteration, surface water quality, shallow groundwater and the application of reclaimed effluent. Findings. Individual Master Plan facilities will require site-specific CEQA review prior to construction. Such reviews would identify measures to avoid potential hydrologic impacts or reduce them below a level of significance. -5- ~o6.o90 B. NORTH TWIN OAKS RESERVOIR ANALYSIS 1. Bioloev Impacts. Construction of the proposed reservoir at Site No. 1 would result in significant impacts to successional Diegan sage scrub habitat. No significant biological impacts would occur from reservoir construction on Site No. 2. Findings. Development of Site No. 1 would require avoidance of Diegan sage scrub habitat to the extent possible, revegetation of graded areas with sage scrub species, and appropriate offsite habitat replacement. These measures are considered sufficient to reduce potential impacts below levels of significance. 2. Air Ouality and Odors Impacts. While significant project-direct impacts are not expected due to the short-term and incremental nature of projected emissions, additional technical study will be required to verify this assumption. Additionally, implementation of the proposed reservoir project may contribute to significant cumulative impacts due to the non-attainment status of the San Diego air basin. Findings. Implementation of the proposed project will require detailed site-specific evaluation of air quality impacts. It is anticipated that project-specific impacts would be reduced below a level of significance through mitigation identified in this analysis, with specific measures likely to include dust control, proper equipment maintenance, bonding, and restriction of construction traffic to off-peak periods. Contributions to potentially significant cumulative air quality impacts are considered unmitigable. -6- vo. o6.~ 3. Visual Quali .ty Impacts. Construction of the proposed reservoir would result in significant impacts to visual quality at either alternative site. This conclusion is based on the size of the proposed facility, the associated landform modifications, and the generally undeveloped nature of the project area. Findings. A number of mitigation measures are identified for the proposed reservoir at either site, including the use of landscape screening, contoured grading, and visually compatible enclosures for above-ground ancillary facilities. These measures would reduce impacts below a level of significance at Site No. 2, although significant unmitigated impacts would remain for Site No. 1. Noise o Impacts. Construction of the proposed reservoir would result in potentially significant noise impacts from truck traffic, equipment operation and blasting at either alternative site. Although these impacts are short-term in nature, they are considered significant due to the proximity of local residents and the relatively low ambient noise levels in the project area. Findings. Implementation of the proposed project will require a detailed acoustical analysis by a qualified consultant. Mitigation such as the use of bUffers and time restrictions will be employed as a result of this investigation, although it is anticipated that significant noise- related impacts would remain. Traffic Circulation Impacts. Potential impacts associated with the proposed reservoir would be limited to short-term construction-related traffic at either alternative site. While such impacts are not considered significant in -7- ~06.099 06/28/91 a project-direct sense, they could contribute to significant cumulative impacts associated with other local development. Findings. Mitigation measures identified to reduce potential traffic impacts include restriction of construction activities during peak traffic periods and maintenance of through local traffic circulation and parking levels. Despite these measures, however, the project may contribute to significant cumulative traffic impacts. 6. Geology and Soils Impacts. The proposed reservoir would be subject to significant impacts at either alternative site related to seismic hazards, the instability of soil or geologic units, excess or oversize material, and shallow bedrock or groundwater. Findings. Implementation of the proposed project would require site- specific geotechnical review. It is expected that mitigation identified during such investigation would reduce all potential impacts below a level of significance. 7. Hydrology/Water Quality. Impacts. Construction of the proposed project would result in potentially significant impacts at either alternative site related to drainage alteration, runoff flows and velocities, increased erosion hazards, downstream flooding potential, intersection of shallow groundwater, and reduction of water quality. Findings. Implementation of the proposed project would require site- specific hydrologic review. It is expected that mitigation identified during such investigation would reduce all potential impacts below a level of significance. -8- II CHANGES OR ALTERATIONS ASSOCIATED WITH OTHER AGENCIES A. MASTER PLAN Changes or alterations within the jurisdiction of other agencies would be associated with land use and public services and utilities. Specifically, local planning agencies will be responsible for implementing appropriate land use designation and zoning requirements within their jurisdictions, including measures to maintain allowable density allocations and limit growth. In addition, local jurisdictions will be responsible for the assessment and collection of development fees associated with services such as schools and parks. Bo NORTH TWIN OAKS RESERVOIR The VWD board, having reviewed and considered the information contained in the Final EIR and related documents and records, finds that no changes or alterations contained therein which mitigate or avoid significant environmental effects are the responsibility or within the jurisdiction of another agency. III ALTERNATIVES OR MITIGATION CONSIDERED INFEASIBLE A. MASTER PLAN The VWD board, having reviewed and considered the information contained in the Final EIR and related documents and records, finds that specific economic, social or other considerations make infeasible project alternatives for water services identified in the Final EIR as summarized below. No specific economic, social or other considerations were identified which make infeasible either any mitigation measures or the project alternatives identified for wastewater or reclaimed water services in the Final EIR. -9- ~o-o~.~ o~/2s/ol 1. No Pro.~ect The No Project alternative would be inconsistent with planned development strategies within the District, and would severely limit the ability to provide adequate water and wastewater service. This alternative would likely result in service shortfalls as a result of projected population growth and is thus considered infeasible. 2. System Alternatives Water service alternatives including water conservation, desalination, water reclamation, use of groundwater, and operational or emergency storage are not capable of meeting project objectives in and of themselves or in combination. Accordingly, these alternatives are not considered feasible as such. These alternatives are considered valuable additions to proposed water service, however, and the Final EIR recommends implementing them to the maximum extent feasible. B. NORTH TWIN OAKS RESERVOIR The VWD board, having reviewed and considered the information contained in the Final EIR and related documents and records, finds no specific economic, social or other considerations which make infeasible either the mitigation measures or project alternatives identified in the Final EIR. It should be noted, however, that the EIR identifies the need for additional geohydrologic investigation to determine the technical feasibility of using groundwater aquifer storage as an alternative to the proposed reservoir. -10- STATEMENT OF OVERRIDING CONSIDERATIONS The decision maker, pursuant to the CEQA Guidelines, after balancing the benefits of the proposed project against the unavoidable environmental effects identified in the EIR which remain, notwithstanding the mitigation measures and alternatives incorporated into the project, finds and determines that such remaining environmental effects are acceptable due to the following: MASTER PLAN ANALYSIS 1. The Vallecitos Water District proposed Master Plan project provides a comprehensive assessment of existing service capacities, projected demands, and recommended wastewater and reclamation facilities for both a five-year and full community development periods. In addition, the Master Plan provides a recommended infrastructure network to meet projected water, wastewater, and reclamation needs within the service area. 2. The proposed Master Plan determination will not significantly impact existing land uses or land designations in that the ultimate decision of whether development will occur shall be made by the appropriate local planning agencies. The proposed Master Plan facilities will also not generate growth beyond established projections for either the five-year or full development periods. 3. The proposed Master Plan may result in significant impacts to biological resources, visual quality, cultural resources, noise, traffic circulation, geology and soils, and hydrology and water quality. However, the mitigation measures recommended in the EIR will likely avoid impacts or reduce impacts below levels of significance. Final determination of impact levels and the effectiveness of mitigation measures, however, will require site specific CEQA review. 4. The proposed Master Plan may result in air quality and odor impacts that pertain primarily to construction activities and several small pump stations. Mitigation measures are recommended in the EIR but will not reduce the air quality impacts below levels of significance. However, the benefit and necessity of orderly planning to provide for the present and future public facilities of the community that might not otherwise be obtained without implementation of the project outweigh the potential effects and this benefit is considered to be an overriding consideration. -11- NORTH TWIN OAKS RESERVOIR ANALYSIS 1. The proposed North Twin Oaks Reservoir project consists of the construction of a buried reservoir with two alternative sites that would provide the Vallecitos Water District with an additional 52 million gallons of potable water storage. The reservoir is identified in the Master Plan as an important infrastructural need within the District. 2. Alternative 1 of the proposed North Twin Oaks Reservoir project could result in significant impacts to visual quality which cannot be reduced below a level of significance. However, the reservoir project will provide an additional 52 million gallons of potable water storage within the District which is necessary to meet existing and projected operational storage requirements within the Twin Oaks and Richland pressure zone areas. The additional storage capacity will provide critical in-line flexibility with respect to peak demands and supply, and shall serve as a buffer against local capacity short falls and pressure reductions. Therefore, the provision of the improvements under the proposed project will be a substantial benefit to the District and is found to be an overriding consideration. 3. Construction of the proposed North Twin Oaks Reservoir could result in significant impacts related to noise, cumulative traffic levels, and cumulative air quality concerns. These impacts are not subject to mitigation below levels of significance, although the public benefits provided from provision of potable water storage (as described above) are seen to outweigh the stated environmental concerns and therefore are found to be an overriding consideration. -12- REC~.~V~o NORTH TWIN OAKS RESERVOIR VAI,LECITOS WATER DISTRICT MITIGATION MONITORING PLAN Prepared for: Vallecitos Water District 788 San Marcos Boulevard San Marcos, CA 92069 Prepared by: Keller Environmental Associates, Inc. 1727 Fifth Avenue San Diego, CA 92101 June 1991 NI£1T MITIGATION MONITORING PLAN This Mitigation Monitoring Plan is prepared for the Vallecitos Water District's (VWD's) North Twin Oaks Reservoir Project. The project has been described and analyzed in the Vallecitos Water District Water, Wastewater, and Reclamation Master Plan Final Environmental Impact Report (Keller 1991 [SCH # 9001707]) in accordance with the California Environmental Quality Act (CEQA) and State CEQA guidelines. The Final Environmental Impact Report (FEIR) is expected to be certified by the VWD in June, 1991. The purpose of this plan is to ensure that the mitigation measures recommended in the FEIR for the proposed project are implemented and to determine their effectiveness in order to guide future decisions. While more specific mitigation measures will be developed when detailed project design information becomes available, this monitoring plan establishes the framework necessary to monitor the implementation of mitigation measures. PROJECT DESCRIPTION SUMMARY The proposed project consists of two cast-in-place, reinforced concrete tanks which will have a combined storage capacity of 52 million gallons. Construction of the reservoir will require approximately three years, and would involve a variety of construction equipment, including cranes, water trucks, front-end-loaders, bulldozers, utility trucks, scrapers, concrete trucks and drilling and blasting equipment. Two sites are currently being considered for the reservoir, both located in the northern end of Twin Oaks Valley in San Diego County (see Figure 1). Specific project design information is dependent on the site chosen. Both sites are addressed in this report. Site No. 1 Site No. 1 includes approximately 11 acres located west of the Twin Oaks Valley Road/Twin Oaks Crest Drive intersection. This site is the location of the existing Twin Oaks reservoir, an open 7.2 million gallon facility. Two pump stations are located at the eastern end of the site. The proposed project would consist of an 18.3 million gallon tank on the northern portion of the site and a 33.7 million gallon tank on the larger, southern portion of the site. The tanks would contain several independent storage basins, allowing them to have varying - 1- ~oo-o6.o21 Reservoir Site No. 2 I :7 .... -. ROAD V2 ',) ;,. / / ': J North Twin Oaks Reservoir Mitigation Monitoring Plan Vicinity Map Figure 1 capacities, depending on need. The proposed project would also require other facilities to control and maintain the reservoir, e.g. valve, pipes, meters, etc. Earthwork requirements for the proposed project would entail approximately 78,000 cubic yards (cy) of cut and 60,000 cy of fill, with excess material to be removed from the site and disposed of in an approved location. Maximum proposed gradients would consist of 1.5:1 for cut slopes, 2:1 for fill slopes and 1:1 for backfill slopes. Fill slopes would encircle most of the site, with maximum slope heights of approximately 71 feet. Maximum cut slope heights would be approximately 4 feet. Retaining or crib walls would be used to support a number of the described fill slopes, with approximately 900 linear feet of proposed walls exhibiting maximum heights of 22 feet. Additional project design information is contained in the FEIR. Site No. 2 Alternative Site No. 2 encompasses approximately 17 acres located 200 feet southwest of Site No.1. The site includes undeveloped lands and avocado orchards. The project area is relatively level, although the site slopes moderately to the east. The proposed reservoir at this site would consist of 2 square tanks measuring 365 feet on a side. Similar to the reservoir design for Site No. 1, the tanks would contain separate storage basins. Several off- site pipelines associated with the project would be required. Exact locations for these lines have not yet been determined and will require further CEQA review. As with Site No. 1, other facilities for the operation and maintenance of the reservoir would be required. Site No. 2 will require a new 25-foot wide (total easement width) paved access road extending approximately 1,400 feet from Twin Oaks Valley Road to the southeast corner of the site. The new road will be required due to the steep grade associated with the existing access road. Earthwork requirements for the proposed reservoir would include approximately 67,000 cy of cut and 78,000 cy of fill, with additional fill material imported from off site. Maximum proposed gradients would consist of 1.5:1 for cut slopes, 2:1 for fill slopes and 1:1 for backfill slopes. Manufactured slopes would encircle the site, with maximum heights of approximately 19 feet for cut slopes and 41 feet for fill slopes. -2- ~o. oao2~ o~/n,~ A more detailed description of the proposed project is contained in the FEIR. MONITORING PLAN The VWD is required to monitor all mitigation measures included in the certified FEIR. The monitoring program for the North Twin Oaks Reservoir addresses mitigation measures related to the following areas: Biological Resources, Air Quality, Visual Resources, Noise, Traffic Circulation, Geology/Soils, and Hydrology/Water Quality. A table summarizing significant impacts, mitigation measures and monitoring activities is included at the end of this monitoring plan (see Table 1). The VWD will implement the mitigation monitoring plan and identify a staff person or consultant who will function as a Mitigation Compliance Coordinator (MCC). The MCC's responsibilities include establishing and overseeing the team of technical monitors, conducting on-site monitoring, ensuring that the plan is being implemented on schedule and preparing monthly monitoring reports. The monitoring reports will be filed with the VWD and, when necessary, any other agency with the authority to regulate the reservoir's construction, e.g. the County of San Diego. A Mitigation Monitoring Activity Log, similar to the sample located at the end of this plan (see Figure 2), will be used to record and report monitoring activities. A primary aspect of the MCC's job will be ensuring that aH mitigation measures, permit conditions and any other monitoring, testing and/or reporting required for the project are implemented. In several cases, specific mitigation measures will not be developed until further project design information is available and additional environmental studies are completed. The identified additional measures will be incorporated into a revised version of this plan. -3- ~oao2~ MITIGATION 'ROJECTILOCATION: Figure 2 MONITORING REPORT J_ OATE: [PREPARER: I REPORT NUMBER: DISCIPLINE: MITIGATION MEASURE: OBSERVATIONS: COMPLIANCE: I"] Acceptable [] Unacceptable [] Follow-up Required RECOMMENDATIONS: COMMENTS/ACTIONS: COPY/ISSUED: [] MCC [] CONTRACTOR The MCC will act as the VWD's representative at the project site. The MCC will need to be in contact with the construction foreman and construction manager, particularly where non-compliance with mitigation measures is noted. In an event of non-compliance, the MCC is responsible for immediately informing the costruction manager and VWD of the observation. A record of the communication shall be filed within 24 hours of the event. The District will have authority to delay construction activities while a particular situation is remedied. This will be specified in the construction bid documents and contract. The MCC may also recommend changes or additions to the adopted mitigation measures, although any alteration to the adopted plan would require approval from the VWD prior to implementation. Any change in procedure will need to be reflected in both the MCC's periodic reports and this monitoring plan. The mitigation measures related to the proposed project deal primarily with the reservoir's construction, not its operation. Following completion of the reservoir's construction, the MCC will prepare a comprehensive report describing those monitoring activities which have taken place, observations made, the success of the implemented mitigation measures and recommendations for future mitigation measures. The report will also identify those mitigation measures which have not yet been completed, e.g., the monitoring of revegetation activities, and identify the person(s) responsible for completing those tasks. The comprehensive report will be filed with the VWD. When all monitoring activities have been completed, the MCC will file a final report with the VWD addressing the longer-teml monitoring activities which had not been completed during project construction. One purpose of the monitoring plan is to determine the effectiveness of the recommended mitigation measures. Where applicable, the MCC and/or the appropriate technical consultant will determine if mitigation measures were successful in reducing their respective impacts to levels below significance. These findings will be incorporated in the MCC's reports. In some instances, e.g., measures designed to allow the project to withstand seismic hazards, the failure or success of the measure may not be determined for years after the monitoring program is concluded, depending on regional seismic activity. The following text includes a brief summary of significant impacts and associated mitigation measures as described in the FEIR. Where impacts and/or mitigation differs between site nos. 1 and 2, they will be addressed separately. Where the impact occurs on only one of the sites, only the impacted site will be addressed. Biolo~c~! Resources Impact - Site No. 1 The proposed project would eliminate 2.41 acres of Diegan Sage Scrub, a suitable habitat for the California Gnatcatcher. (No significant impacts were identified at Site No. 2.) Mitigation Measure The Diegan Sage Scrub area should be avoided to the maximum extent possible. Graded areas should be revegetated with sage scrub species. The loss of habitat will be considered si~ificant and unmitigated unless it is replaced off site at a ratio of 1:1. Mitigation Monitoring Site No. 1 The VWD will hire a qualified biologist who will determine the amount of loss of Diegan Sage Scrub based on final grading plans and provide the MCC with a list of acceptable sage scrub species for revegetation. The qualified biologist will inspect the site during irrigation system installation and planting to ensure that the correct species are used to revegetate the graded areas and that they are properly planted. The biologist will also establish a schedule for monitoring. The MCC or biologist will visit the site monthly, or at other intervals determined to be adequate by the biologist, for approximately one year after planting to determine the success of the revegetation effort. Those findings will be included in the MCC's final report. The biologist will establish a plan for an off-site mitigation area to compensate for the loss of Diegan Sage Scrub habitat. This mitigation project, which may include additional monitoring, will require the approval of the VWD in consultation with the County of San Diego. -5- 90-06.021 06/12/91 Air Ouality Impacts Potential air quality impacts associated with the proposed reservoir would consist predominately of short-term construction-related effects. These would include exhaust emissions from construction equipment and fugitive dust generation from soil movement during grading operations. The levels of emissions which would be generated by the proposed project are considered incremental on a local or regional basis and are not considered significant. Because of the non-attainment status of the San Diego Air Basin, however, the incremental increase of exhaust emissions associated with construction operations would contribute to potentially significant cumulative degradation of local air quality. Mitigation Measures The proposed project will require detailed site-specific evaluation of potential air quality impacts by a qualified meteorologist after completion of the final project design. Depending on the exact nature of final design, a number of mitigation measures may be recommended in the site-specific evaluation, including those listed in the FEIR. Mitigation Monitoring The VWD will hire a qualified meteorologist to develop site-specific mitigation measures after the final project design has been completed. The measures, which are anticipated as being similar to those identified in the FEIR, will require approval from the VWD and be incorporated into this mitigation monitoring plan. The MCC or meteorologist will inspect the site on a weekly basis to determine if the air quality mitigation measures are being followed and effective. Due to the cumulative nature of the impact, the effectiveness of these measures at a regional level can not be determined. -6- oo-o~o2~ Visual Ouality Impacts Site No. 1 The proposed project would create significant impacts to landscape character and scenic quality due to the proposed landfo,,~ modification required for the reservoir's construction and the size of the proposed facility compared to the existing structure. The significant visual impacts are expected to be incurred by local residents and travellers on Twin Oaks Valley Road, a San Diego County designated third priority scenic route. Site No, 2 _The proposed project would create significant impacts to landscape character and scenic quality at Site No. 2. The visual impacts of the proposed project would be considered less significant at this site, since the site is less visible than Site No. 1. The visual impacts would be incurred primarily by local residents. Mitigation Measures Mitigation Measures for Site Nos. 1 and 2 are primarily related to the treatment of the retaining walls, fill slopes and cover of the reservoirs. Mitigation measures for the two sites include the following: All new above-ground ancillary facilities (e.g., valves, pump stations, etc.) should be landscaped or enclosed in structures to reduce the industrial character of the facility. A landscaping plan should be developed that emphasizes a ~natural hillside" setting for the reservoirs. The landscape plan should be developed by a registered landscape architect, and include measures to visually screen the parking lot and other industrial features. Use of irrigation for rapid establishment of trees, scrubs, and native vegetation on slopes should be incorporated into the plan. In the event that Site No. 1 is chosen, the landscape plan will incorporate coastal sage scrub to revegetate the site, as required under the biological resources mitigation requirements. -7- 9o-o~o2~ It is suggested that the final grading plans utilize grading techniques that would minimize any strong geometrical landfo,ms and would blend the landfoim modifications with the natural existing rolling topography. - Mitigation Monitoring The VWD will hire a registered landscape architect to develop and implement the landscape plan described under Mitigation Measures. The MCC will examine project design plans prior to the start of construction to ensure that above-ground facilities will be landscaped and/or enclosed. The MCC will inspect the site after construction is completed to ensure that those plans were carried out. The landscape architect will be responsible for monitoring the successful implementation of the landscape plan. It is expected that this plan will include measures for blending landfmm modifications with the natural existing rolling topography. When the project site is undergoing the installation of the irrigation system and planting, the landscape architect will be present to observe the initial installation and visit the site on a regular basis for one year to ensure the success of the planting. The frequency of these inspections will be jointly determined by the MCC and landscape architect. The MCC is responsible for coordination between a qualified biologist and the registered landscape architect in the preparation of a suitable landscaping plan. One year after the construction on the proposed project is completed, the MCC will inspect the site to determine the success of the landscaping. These observations will be included in the MCfYs final report along with those of the biologist and landscape architect. Noise _ Impacts Potentially significant impacts from the proposed reservoir would be associated primarily with construction activities. Construction equipment requirements would likely involve heavy earth moving equipment, concrete and water trucks, stationary generators or compressors and drilling and blasting equipment. Noise levels could vary considerably depending on the required extent and location of blasting. Both construction and blasting activities would probably result in significant noise impacts to single residences located appro~raately 20 feet east of Site No. 1 and within the northwestern corner of Site No. 2, respectively. While impacts to other residences near the project area and along the truck routes to and from the site would not be significant, over the course of construction, i.e., three years, the noise increase could be considered intrusive. Mitigation Measures A detailed acoustical investigation will be conducted by a qualified acoustician for the proposed project after site selection and final project design. The results and recommendations of this investigation will be incorporated into construction specifications and this monitoring plan for the proposed reservoir, and are likely to include the following types of measures: Appropriate buffers, barriers and other noise reduction methods will be employed during construction activities pursuant to direction by a qualified noise consultant. This may include restricting operations in certain areas or use of noise barriers such as temporary walls or berms. Construction activities will not occur between 7 p.m. and 7 a.m. and all day on Sundays and holidays except in an emergency with authorization of the VWD. Mitigation Monitoring The VWD will hire a qualified noise consultant to conduct the acoustical investigation and to develop recommendations to be incorporated into the construction operations. The MCC will ensure that these recommendations are incorporated into construction operating procedures before construction begins. The MCC or noise consultant will make weekly inspections of the project site to ensure that the recommended measures are being implemented. The noise consultant will report his/her findings to the MCC on a monthly basis. The area residents will be informed, e.g., by doorknob hanger, of the hours of construction and will be given an phone number and/or address to which they may lodge complaints. The MCC will be responsible for investigating, or dispatching a qualified noise consultant to investigate, such complaints. The noise consultant's reports will be summarized by the MCC in the comprehensive report which the MCC will file with the VWD after the completion of construction activities. -9- ~o~o2~ oo/~2,~ Traffic Circulation Impacts Traffic impacts during construction will be limited to staffing and materials delivery, assuming that no blockage of local roadways will be required. The reservoir's operation will not produce traffic impacts. Potential construction traffic impacts to the surrounding street system are not anticipated to be significant due to the short-tem~ and incremental nature of additional trips. It should be noted, however, that construction traffic related to the proposed reservoir may contribute to significant cumulative impacts associated with other local development. Mitigation Measures Despite the finding of no significant traffic impacts, the following mitigation measures are recommended to reduce potential impacts to local circulation. Hauling of materials and other activities associated with the proposed reservoir which add truck traffic to local streets should be restricted to off peak periods to avoid additional delays. Peak hours are generally defined as the periods between 7:00 and 9:00 a.m. and between 4:00 and 6:00 p.m. Construction activities will be conducted such that through traffic and local access and/or parking will not be precluded. Mitigation Monitoring The MCC will conduct periodic site inspections to ensure that the mitigation measures are being enforced. It should be noted that the cumulative effect of the noise and traffic mitigation measures is to minimize truck traffic associated with the proposed project from the local roadways before 9:00 a.m. Impacts Potential geologic impacts related to the proposed reservoir include seismic hazards to project facilities, the instability of certain soil and geologic units, and construction hazards related to excess or oversize material and shallow bedrock or groundwater. Seismic Hazards Ground Acceleration Maximum ground acceleration values are associated with a magnitude 7.6 earthquake along the Elsinore Fault Zone. Such an event would be expected to generate Modified Mercalli Scale intensities of up to IX, potentially resulting in significant damage to structures and underground facilities. Landsliding The proposed reservoir would involve substantial grading and the construction of sizable fill slopes. Such slopes could be subject to seismically-induced landsliding during a major earthquake, potentially resulting in damage to associated facilities and discharge of stored water. Seiches The proposed reservoir may be subject to seismically-induced seiche impacts, potentially resulting in structural damage and downstream inundation. (A seiche is a occasional and sudden oscillation in a body of water, e.g., as caused by an earthquake.) The proposed design includes a number of measures to reduce such potential impacts, including the use of individually contained basins within the reservoir. Final project design would also include inundation and spill contingency studies related to catastrophic events (i.e., earthquakes). Depending on final design parameters, the proposed project may be subject to review by the California Division of Dam Safety. Non-Seismic Hazards Expansion Expansive behavior within the proposed sites could result in significant damage to foundations, fill slopes and associated facilities. - 11- ~o6.o2~ Erosion The proposed reservoir would entail substantial grading, excavation, and construction of manufactured slopes. Fill slopes and graded areas are generally susceptible to effects such as rilling and unde,mining due to the granular cohesionless nature of fill and the lack of stabilizing vegetation. Such effects can result in a loss of support for facilities associated with fill slopes, exposure of, and damage to, underground facilities, and the off- site transport of sediment. Compaction and Settlement The project sites may be susceptible to compaction and settlement effects due to the loose nature of many surficial deposits and the potential occurrence of subsurface oversize materials. Potential impacts related to this phenomenon include damage to structures and fill slopes. Reactive Soils Several native soils within the project sites exhibit corrosive potential due to acidic or alkaline soil chemistry. These materials pose potentially significant impacts to project facilities in the form of deterioration .or failure of underground concrete and metal structures. Construction Related Hazards Construction activities associated with the proposed project may involve a number of additional impacts related to geology/soils as described below. Shallow Bedrock Shallow bedrock may be encountered during excavation activities at the proposed project sites. Bedrock underlying the project sites includes resistant igneous intrusives which would probably require ripping and/or blasting. .Shallow Groundwater Shallow groundwater is not expected to occur within the project sites due to topographic and hydrologic considerations. Should locally perched groundwater be present, however, it could result in potential impacts related to construction activities (through flooding of excavations, etc.) and water disposal. Disposal of extracted groundwater, if necessary, would require coordination with the Regional Water Quality Control Board (RWQCB). Material Disposal Proposed excavation activities may require off-site disposal of materials which are unsuitable for use as fill. This disposal could result in impacts to local roadways and traffic, as well as effects from the use of improper disposal sites or techniques (e.g., disposal in areas subject to erosion or improper covering during transportation). .Oversize Material Oversize rock may be generated locally as a result of proposed excavation activities. Such materials could impact proposed facilities by producing differential settlement if utilized in structural fills. Gravity-Induced Landsliding The generation of temporary (construction) and pe~laanent manufactured slopes on site would create the potential for non-seismic (gravity-induced) landsliding. Mitigation Measures Ail impacts related to geology/soils can be reduced below levels of significance through standard design and construction measures. These design and construction measures will be described in a site-specific geotechnical investigation. The investigation will be conducted by a qualified geologic consultant prior to project implementation. The site- specific evaluation will include surface, subsurface and laboratory analysis to identify hazards related to seismicity (including potential effects from liquefaction, ground acceleration, landsliding, and seiches), the stability of surficial and geologic units, and construction related effects. The results of these studies will be used in the project design, including all mitigation measures developed by the geotechnical consultant to avoid or reduce impacts. Several possible mitigation measures are described in the FEIR, although the actual measures to be implemented will be determined by the geological consultant and included in this monitoring plan. Mitigation Monitoring The VWD will hire a qualified geological consultant to oversee/perform the necessary analysis of the chosen site. The consultant will work with the project design engineers to ensure that the project design reduces potential geology/soils impacts to levels below significance. The MCC and the geotechnical consultant will review project design plans prior to the start of construction to confirm that potential impacts from geotechnical constraints have been sufficiently mitigated. Throughout the course of construction, the MCC will monitor construction to verify that design measures intended to mitigate geology/soils constraints are being implemented. The MCC may require that the geotechnical consultant perform site inspections during construction if the MCC can not adequately determine the success of geotechnical mitigation measures. Where applicable, the MCC's periodic and post-construction comprehensive reports will contain summaries of the effectiveness of the mitigation measures. Hydrology./Water Ouality Impacts Surface Water Proposed surface grading would affect the direction, volume and velocity of runoff within and leaving the project site. It is considered unlikely that these effects would be significant, although a detailed site-specific hydrological analysis will be required to verify this finding. The proposed reservoir will contain up to 52 million gallons of water, and a potential breach of this facility or associated pipelines could result in significant downstream flooding impacts. Preliminary project design includes a number of features to reduce potential flooding impacts, including the use of individually contained and operated basins within the reservoir and a series of control and shut-off valves. Final project design will also include detailed inundation and contingency studies to identify specific flooding impacts associated with a potential breach. It is expected that these studies, and associated design recommendations, will reduce potential flooding impacts to a level below significance. This finding will require verification by a qualified hydrologist. The proposed project would increase erosion potential on and off site through disturbance of surficial deposits, removal of stabilizing vegetation, use of construction fill and increased runoff volumes and velocities. Unchecked erosion could result in substantial sediment transport, destabilization of slopes (and related project facilities) and sedimentation of off- site drainage courses. The significance of these impacts will need to be determined by a detailed hydrological evaluation conducted by a qualified hydrologist. Groundwater No groundwater impacts are expected to occur. If shallow groundwater is encountered during construction, it could pose adverse impacts through flooding of excavations and limitations to vehicular access (i.e., from muddy conditions). Water Quality The proposed project could be expected to generally decrease surface water quality both within and downstream of the site. The water quality degradation would generally involve both long- and short-term effects related to erosion, sedimentation and construction as well as potential discharges of hazardous construction materials. These potential effects are primarily restricted to surface waters, with potential impacts to groundwater quality limited to material discharges. Construction-related effects pose the most significant potential impacts to water quality from the proposed project. Large scale excavation and grading and the construction of manufactured slopes would increase the potential for erosion and transport of materials within and off the site. The movement of sedimentary materials into local drainages could produce significant local siltation impacts. Specifically, the influx of such materials would be expected to increase the quantity of contaminants such as total solids, inorganic constituents and turbidity. Depending on the quantity and duration of siltation effects, construction-related sediment loss from the site could contribute to the cumulative degradation of local water quality and associated resources (e.g., biological habitats). An additional potential impact to water quality associated with construction activities involves the discharge of hazardous materials directly or indirectly into drainage systems. Hazardous materials include materials such as fuels, lubricants and construction compounds (e.g., concrete residue, sealants, etc.). The discharge of such materials could produce significant impacts to surface water quality, as well as groundwater, if present, and associated resources. Potential long-term erosion of developed areas would result from the removal of native vegetation and topsoils, the use of construction fill and the alteration of local runoff patterns and quantities. Continued erosion would reduce local water quality directly through increased sediment loads, and indirectly through the presence of small diameter particle which provide loci of adherence for other contaminants (e.g., organic and petroleum compounds). Mitigation Measures Prior to final design for the proposed reservoir, a detailed hydrological investigation will be conducted by a qualified hydrologist or civil engineer. This investigation will include evaluation of surface and subsurface hydrologic environments to determine site-specific effects related to drainage alteration, runoff values, flooding, erosion potential, groundwater resources and water quality. The recommendations of this study will be incorporated into final project design, including all mitigating measures identified to preclude or reduce impacts. The mitigation measures will also be incorporated into this monitoring plan. Several possible mitigation measures are described in the FEIR. Mitigation Monitoring The VWD will hire a qualified hydrologist or civil engineer to perfmm the detailed analysis described under Mitigation Measures. The MCC will verify that the mitigation measures which result from that investigation are incorporated into the project design prior to the start of construction. The MCC will include those mitigation measures in this monitoring plan. The MCC will inspect the construction site on a weekly basis to ensure that mitigation measures designed to preclude or reduce water quality are being followed, including the provision that potentially hazardous materials are properly disposed. SUMMARY The VWD will hire/appoint a MCC to ensure that the mitigation measures identified in the FEIR and this monitoring plan are implemented. The MCC will oversee all monitoring activities and report regularly to the VWD on the status of mitigation measures. This monitoring plan will need to be expanded to include all mitigation measures that are developed by the MCC or consultants as a result of additional technical studies which will be conducted for this project. A table summarizing impacts, mitigation measures and mitigation monitoring is included at the end of this report, as is a sample Mitigation Monitoring Report (Table 1 and Figure 2, respectively).