Water Resources and Water Quality

GOAL 3. Ensure the availability of adequate surface and groundwater resources to meet existing and future domestic, agricultural, recreational, and natural resource needs in Mono County.

Objective 3.A.

Continue to develop a comprehensive countywide water resource database.

Policy 3.A.1. Compile baseline data and assessments on the basic components of watersheds and their hydrologic units including groundwater basins, within the county.

Action 3.A.1.a. Cooperate with relevant agencies and organizations to develop and maintain a comprehensive hydrologic record of watersheds, hydrologic units and groundwater basins.

Action 3.A.1.b. Reference local watershed assessments and other available data for existing conditions and incorporate assessment results into resource management planning.

Action 3.A.1.c. Continue to support and implement the California Statewide Groundwater Elevation Monitoring (CASGEM) program and comply with the requirements of the Sustainable Groundwater Management Act of 2014 (SGMA).

Action 3.A.1.d. Work with local water providers, LADWP, the Tri-Valley Groundwater Management District, Walker River Irrigation District, Lahontan RWQCB and other water and resource management agencies to calculate water budgets[2] and develop water management plans for each watershed in the county.

Action 3.A.1.e. Support research and monitoring to better understand impacts of water-related projects on environmental resources.

Objective 3.B.

Identify and secure adequate water for future local domestic needs while maintaining natural resources.

Policy 3.B.1. Assist and encourage the communities of Mono County and local special districts to secure additional water rights within local water basins as necessary for the orderly growth of local communities.

Policy 3.B.2. Encourage the preparation of water management plans by local water providers.

Action 3.B.2.a. Assist special districts in securing available grant moneys for water management planning.

Policy 3.B.3. Encourage the USFS and the BLM to assist local communities in securing the water resources necessary to accommodate community demands, particularly those demands that directly and indirectly result from increased activities on adjacent federal lands.

Action 3.B.3.a. Review and comment on development proposals on federal lands and require full environmental review on out-of-drainage transfers.

Policy 3.B.4. Work with small water systems to comply with state and federal requirements.

Action 3.B.4.a. Continue to support regional cooperative efforts to pursue funding for development, implementation, monitoring, and long-term maintenance of small water systems.

Policy 3.B.5. Encourage the consolidation of small water providers to increase operational and service efficiency.

Action 3.B.5.a. Require new developments to be served by existing water providers, where feasible, rather than creating new service entities.

Policy 3.B.6. Future development projects shall avoid potential significant impacts to local surface and groundwater resources or mitigate impacts to a level of non-significance, unless a statement of overriding considerations is made through the EIR process.

Action 3.B.6.a. Future development projects with the potential to significantly impact surface or groundwater resources shall assess any potential impacts prior to project approval. Examples of potential significant impacts include:

1. substantially degrading or depleting surface or groundwater resources; and/or
2. interfering substantially with groundwater recharge.

The analysis shall:

1. be funded by the applicant;
2. be prepared by a qualified person under the direction of Mono County;
3. assess existing conditions in the general project vicinity;
4. identify the quantity of water to be used by the project. Quantities shall be estimated for annual totals, monthly averages, and peak day/peak month usage;
5. identify the source(s) of water for the project and provide proof of entitlement to that water. If the proposed source is to be a special district or mutual water system, a "will-serve" letter shall be required. If the proposed source is ground or surface water, the application shall indicate that the proponent has entitlement to the source and the quantity of water required;
6. describe the impacts of the proposed development upon water resources within the project site and on surrounding areas, including a drawdown analysis of groundwater (when applicable) through pump test(s); and
7. recommend project alternatives or measures to avoid or mitigate impacts to water resources.

Mitigation measures and associated monitoring programs shall be included in the project plans and specifications and shall be made a condition of approval for the project.

Policy 3.B.7. Limit development to a level that can be reasonably supported by available local water resources.

Action 3.B.7.a. Require development projects to obtain "will serve" letters from applicable service agencies.

Action 3.B.7.b. For areas not served by an existing water system, require future development projects to demonstrate, prior to permit issuance, that sufficient water exists to serve both domestic and fire-flow needs of the development and that use of that water will not deplete or degrade water supplies in the area, or adversely impact natural resources.

Action 3.B.7.c. Deny development projects that have not demonstrated the availability or entitlement to a supply of water adequate to meet the needs of the proposed project and as required by SB 610 and SB 211.

Objective 3.C.

Conserve Mono County’s water resources and water supply while maintaining ecosystem health through water conservation programs.

Policy 3.C.1. Encourage reduced water consumption in residential and nonresidential properties.

Action 3.C.1.a. Encourage and promote the installation of residential gray-water systems on existing residential and commercial properties that meet appropriate regulatory standards.

Action 3.C.1.b. Encourage installation of water conservation measures, including recycled water projects where feasible, in new and existing homes, businesses and County facilities.

Action 3.C.1.c. Encourage new residential and commercial construction and new County facilities to exceed CALGreen water conservation requirements.

Action 3.C.2.d. Encourage prospective homebuyers to conduct water efficiency audits at point of sale for commercial and residential properties.

Action 3.C.2.e. Assess, maintain, repair, and program existing irrigation systems to minimize water use, including parking lot landscaping, public restrooms and parks, and recreational facilities.

Action 3.C.2.f. Encourage and support regional water conservation strategies through partnerships such as the Inyo Mono Integrated Regional Water Management Group.

Policy 3.C.3. Water intensive development proposals shall include water conservation measures as a condition of approval of the project.

Action 3.C.3.a. Implement the Water Efficient Landscape Ordinance.

Policy 3.C.4. Encourage effective water conservation programs for communities outside Mono County that benefit from water resources originating in the county.

Objective 3.D.

Protect the Public Trust values of the resources of Mono County. (The Public Trust doctrine recognizes that some types of natural resources are held in trust by government for the benefit of the public. Water resources have been recognized historically as a resource subject to the public trust.)

Policy 3.D.1. Encourage and support agencies responsible for reviewing water rights applications to consider the effects of existing and proposed water diversions upon interests protected by the Public Trust.

Action 3.D.1.a. If necessary, file formal protests with the State Water Resources Control Board when the County determines that granting a water rights application would be harmful to Public Trust values.

Action 3.D.1.b. Require water projects that may impact Public Trust values to avoid or mitigate those potential adverse impacts.

Policy 3.D.2. Oppose any legislative or regulatory efforts to undermine or weaken protection afforded to county water resources by the Public Trust.

Objective 3.E.

Encourage the beneficial use of water resources while protecting local water users and biological resources from the adverse effects of water transfers.

Policy 3.E.1. Regulate out-of-basin water transfers from private lands in the unincorporated area of the county, in accordance with the following actions.

Action 3.E.1.a. Where not preempted by state law, require a water transfer permit from the Mono County Planning Commission for out-of-basin water transfers.

Action 3.E.1.b. Applications for permits for out-of-basin water transfers shall be submitted to the county Planning Division and shall include the following information:

1. point of extraction;
2. amount of extraction;
3. nature and location of conveyance facilities; and
4. identification of potential impacts to the environment such as wildlife and riparian habitat, wetlands, in-stream habitat, other water users (e.g., agricultural operators), and also including indirect effects such as the potential for increased flood risk due to reduced wetlands, and increased fire hazard risk that could result in increased sedimentation and reduced groundwater recharge capacity.

Applications for water transfer permits shall include a processing fee, together with applicable environmental fees.

Action 3.E.1.c. In addition to the Groundwater Transfer Ordinance findings, the Planning Commission shall make the following findings to issue a water transfer permit:

1. That the proposed project meets all reasonable beneficial water needs, including uses in-stream and for agricultural operations and recreational purposes, within the basin of origin; and
2. That the proposed project adequately protects water quality, in-stream flows, lake levels, riparian areas, vegetation types, sensitive/rare wildlife and habitat, and related resources such as the visual quality and character of the landscape; and is not likely to increase indirect effects such as flooding, wildfire, and/or sedimentation, or reduce groundwater recharge capacity. Projects that do not adequately protect these resources shall be denied.

Action 3.E.1.d. The Planning Commission shall review all water export projects in the unincorporated area for consistency with the County General Plan and any applicable Area Plans.

Policy 3.E.2. Implement the Groundwater Transfer Ordinance for out-of-basin groundwater transfers, and consider other local mechanisms to regulate groundwater exports including the provisions of the Sustainable Groundwater Management Act.

Action 3.E.2.a. Initiate the process to establish local Groundwater Sustainability Agencies where required by law to monitor groundwater use and regulate out-of-basin groundwater transfers in appropriate areas of the county.

Action 3.E.2.b. Applications for groundwater export projects shall obtain a Groundwater Transfer permit (Mono County Code section 20.01), which requires the assessment of the potential impacts of the project prior to project approval in accordance with CEQA, and requires findings to be made. In addition, indirect impacts of increased wildfire risk and sedimentation resulting from fire, and increased flood risk and reduced recharge rates due to reduced or degraded wetlands and riparian areas, should be considered.           

Policy 3.E.3. Oppose federal and state legislation and regulations that provide preferential status to out-of-county water appropriators or that allow for increased water diversions from Mono County.

Policy 3.E.4. Evaluate participation in the Walker Basin Restoration Program (WBRP).

Action 3.E.4.a. Pursue funding with the National Fish and Wildlife Foundation (NFWF) to collect and analyze all the information necessary for the County to determine if and how participation in the WBRP may be possible, including full CEQA review to assess the potential effects on various resources, a potential pilot water transaction program, and any necessary General Plan policy updates.

Action 3.E.4.b. Ensure any participation in the WBRP is consistent with General Plan policies, particularly the area plan polices for the Antelope and Bridgeport Valleys, and policies to protect agricultural uses and natural resources.

Objective 3.F.

Promote the restoration and maintenance of Mono Lake, tributary streams, and downstream areas of the aqueduct system in Mono County, including Grant Lake, the Upper Owens River, Crowley Lake, and the Owens River Gorge.

Policy 3.F.1. Work with the appropriate agencies to develop and implement a comprehensive water management plan for Mono Basin and the downstream areas of the aqueduct system. The water management plan should ensure that Mono Lake and the local aqueduct system are managed in a manner that protects the ecological and fisheries values of the Mono Basin and downstream areas of the aqueduct system.

Action 3.F.1.a. Support the State Water Resources Control Board Decision 1631 requiring minimum flows to Mono Lake to maintain the lake level over 6,391 feet above mean sea level.

Action 3.F.1.b. Support management of the aqueduct system that avoids drastic fluctuations in stream flows.

Action 3.F.1.c. Ensure that any comprehensive water management plan developed as per Policy 1, above, is consistent with the USFS's existing Comprehensive Management Plan for the Mono Basin National Forest Scenic Area.

Action 3.F.1.d. Manage Crowley Reservoir to protect its fishery and recreational opportunities.

Action 3.F.1.e. Manage the Upper Owens River to protect the quality of the fishery.

Objective 3.G.

Reestablish streams impacted by diversions in the Mono Basin and Long Valley hydrologic units with flows adequate to support fish populations, riparian habitat, and associated recreational and scenic values.

Policy 3.G.1. Support minimum flows in all streams impacted by water diversions.

Action 3.G.1.a. Review technical documents prepared for the Mono Basin, Upper Owens, and Crowley Lake areas in order to provide input to the LADWP's water management plan on a periodic basis.

Policy 3.G.2. Provide land use controls that facilitate the restoration of impacted stream channels and adjacent areas.

GOAL 4. Protect the quality of surface and groundwater resources to meet existing and future domestic, agricultural, recreational, and natural resource needs in Mono County.

Objective 4.A.

To the extent not preempted by State or Federal law, preserve, maintain, and enhance surface and groundwater resources to protect Mono County's water quality and water-dependent resources from the adverse effects of development and degradation of water-dependent resources, including compliance with AB 685.

Policy 4.A.1. Future development projects shall avoid potential significant impacts to water quality in Mono County, or mitigate impacts to a level of non-significance unless a statement of overriding considerations is made through the EIR process.

Action 4.A.1.a. Future development projects with the potential to significantly impact water quality shall assess the potential impact(s) prior to project approval. Examples of potential significant impacts include:

1. substantially degrading water quality; and/or
2. contaminating a public water supply; and/or
3. causing substantial flooding, erosion or siltation.

In areas determined by the County to be of special significance, such an analysis and associated mitigation measures may be required even if the proposed project conforms to water quality standards established by the Lahontan Regional Water Quality Control Board for the project area.

The analysis shall:

1. be funded by the applicant;
2. be prepared by a qualified person under the direction of Mono County;
3. assess current water quality in the general project vicinity;
4. describe the impacts of the proposed development upon water quality within the project site and on surrounding areas, including a quantification of potential runoff and sedimentation from erosion, contamination that could enter the surface or groundwater system, calculations or mapping related to flooding, and potential cumulative  on-site and off-site hydrologic effects on water quality;
5. for projects with the potential to significantly affect groundwater resources, the analysis may be required to include hydrologic mapping, studies of water flows, groundwater resources, aquifer properties, and baseline quality data; and
6. recommend project alternatives or measures to avoid or mitigate impacts to water quality, including a plan for long-term monitoring of water quality.

Mitigation measures and associated monitoring programs shall be included in the project plans and specifications and shall be made a condition of approval for the project.

Policy 4.A.2. Control erosion at construction projects.

Action 4.A.2.a. Ensure that Lahontan Regional Water Quality Control Board regulations for erosion control are met as a condition for County permit approvals.

Action 4.A.2.b. Work with Lahontan to develop standards and regulations for specific areas of the unincorporated area. Reflect these standards in applicable County regulations, such as the Grading Ordinance (Chapter 13.08).

Action 4.A.2.c. Work with Lahontan to enforce erosion control standards for development on private land.

Action 4.A.2.d. Require posting of a performance bond in compliance with the county Grading Ordinance.

Action 4.A.2.e. Work with Lahontan in the development and revision of erosion- control standards.

Policy 4.A.3. Adjust current practices that cause excessive erosion in order to avoid or mitigate such erosion.

Action 4.A.3.a. County staff and contractors shall follow County grading standards when maintaining County roads, rights of way, and property.

Action 4.A.3.b. Request that state and federal agencies enforce requirements to minimize erosion.

Action 4.A.3.c. Promote the use of cattle fences, appropriately designed to minimize wildlife impacts (see Biological Resources policies), and fish screens in range areas next to streams and lakes where scientific data and management policies indicate the practice to be beneficial to wildlife and livestock.

Action 4.A.3.d. Consider amending the county Grading Ordinance to address water quality concerns.

Policy 4.A.4. Establish buffer zones where recharge occurs, including adjacent to surface waters, wetlands and riparian areas. As required by State law, rivers, creeks, streams, flood corridors, riparian habitats and land that may accommodate floodwater for purposes of groundwater recharge and stormwater management are identified in the County’s general plan maps at https://monomammoth.maps.arcgis.com/home/, which include FEMA and National Wetland Database maps.

Policy 4.A.5. Projects within 30 feet of or that may otherwise impact wetland or riparian vegetation shall implement best management practices as recommended by the State Water Quality Control Board.

Policy 4.A.6. Discourage development within 30 feet of recharge, riparian, and wetland areas to minimize trampling, erosion and siltation impacts, and consider amending the General Plan to specify use and setback requirements. Continue to enforce setback requirements from surface waters.

Policy 4.A.7. Continue to support “no net loss” of wetlands at a regional scale.

Action 4.A.7.a. Establish policies for the management of wetlands in Mono County, including cooperation and compliance with state and federal agencies that manage wetlands.

Action 4.A.7.b. Continue collaborating with applicable agencies to monitor the status of wetlands, such as annual reporting to the Lahontan Regional Water Quality Control Board.

Policy 4.A.8. Manage stormwater runoff to protect water quality throughout communities.

Action 4.A.8.a. As required by the Lahontan Regional Water Quality Control Board, projects must provide post-construction stormwater management plans. Developers should utilize stormwater control measures that are compatible with low-impact development solutions (see General Plan Appendix), such as rain gardens, green roofs, detention ponds, bioretention swales, pervious pavement, vegetated infiltration ponds, and other measures provided by the California Stormwater Quality Association (www.casqa.org) to effectively treat post-construction stormwater runoff, help sustain watershed processes, protect receiving water, and maintain healthy watersheds.

Action 4.A.8.b. Use non-toxic fertilizers in County parks and landscaped areas to reduce potential water quality issues through stormwater runoff.

Action 4.A.8.c. Maintain drainage systems associated with roads and public infrastructure for stormwater management.

Action 4.A.8.d. Complementary design features with the potential to improve habitat such as settling basins, vaults, and bank stabilization should be considered when designing or maintaining culverts. Culverts should be analyzed and designed to limit unintended adverse impacts such as degraded water quality, erosion and siltation of wetlands.

Action 4.A.8.e. Subject to the availability of County resources, provide education and advice on LID measures that could be incorporated into project designs.

Action 4.A.8.f. Update the Mono County Grading Ordinance to ensure consistency with Lahontan Regional Water Quality Control Board regulations.

Policy 4.A.9. Drill holes, such as those that are used for mining, geothermal development, structural investigation, and water development, shall be abandoned and plugged in conformity to state requirements for the protection of groundwater resources and public health and safety.

Objective 4.B.

Protect water from chemical or bacterial contamination.

Policy 4.B.1. Sewage treatment facilities shall be adequate to protect beneficial uses of surface and groundwater.

Action 4.B.1.a. Cooperate with Lahontan to monitor water quality.

Action 4.B.1.b. Encourage federal, state, and local agencies to maintain adequate sanitary treatment capacity at their facilities.

Action 4.B.1.c. Promote the rehabilitation and replacement of aging wastewater infrastructure.

Policy 4.B.2. Promote energy-efficient wastewater treatment and biosolids recycling practices.

Action 4.B.2.a. Work with wastewater service providers to implement an audit, cycling, and equipment-replacement program to increase energy efficiency for water and wastewater pumps and motors.

Action 4.B.2.b. Where feasible, replace septic systems with community package treatment systems.

Policy 4.B.3. Degradation of water quality from livestock shall be minimized.

Action 4.B.3.a. As necessary, investigate the use of fencing, alternate grazing patterns, and/or reduction in the number of animals grazed, or other measures to protect stream water quality and habitat for sensitive species such as the Yosemite Toad and sage grouse (see Biological Resources policies for sage grouse fence design recommendations).

Action 4.B.3.b. Recommend that salt blocks, supplemental food supplies, or chemicals used in treating animals be located sufficiently far from surface water and used in such a manner as to protect water quality.

Policy 4.B.4. Chemicals used for road maintenance should be applied in a manner that does not cause degradation of water quality.

Action 4.B.4.a. County staff and contractors shall not use environmentally damaging methods for de-icing roads.

Action 4.B.4.b. Work cooperatively with other agencies such as Caltrans and the Town of Mammoth Lakes to achieve the most environmentally sound methods of de-icing roads.

Action 4.B.4.c. Request further study of proposed de-icing methods before their widespread use.

Action 4.B.4.d. Enforce Lahontan's standards for road maintenance and weed control; work with other agencies to do the same.

Policy 4.B.5. Use of fertilizer, pesticide, and other chemicals on vegetation or soil in recharge zones should be minimized.

Action 4.B.5.a. Work with the county Agricultural Commissioner and the Natural Resources Conservation Service to institute controls to protect water quality.

Action 4.B.5.b. Work with the county Agricultural Commissioner and the Natural Resources Conservation Service to promote effective and minimal use of chemicals in landscaping and agriculture.

Policy 4.B.6. Assist in the management and control of toxic chemicals or other substances from extractive, industrial, manufacturing, household, or commercial uses.

Action 4.B.6.a. Assist appropriate agencies, such as Lahontan Regional Water Quality Control Board and EPA, in enforcing regulations pertaining to hazardous waste management.

Action 4.B.6.b. Implement hazardous waste management policies in the Integrated Waste Management Plan.

[2]A water budget is a model of the relationship between the inputs and outputs of a particular hydrologic unit.