Priorities: In the event that restoration to the pre-mining use is not feasible, reclamation to provide wildlife habitat is the highest priority. Future use of water from the pits to support neighboring agricultural uses is a desired component for all terrace reclamation plans. The potential for development of public recreational use shall be considered and incorporated in the reclamation plans for the Kaiser South pit area.
Reclamation of existing pits as soon as possible is a high priority. In order for new mining permits to be approved, the operators must demonstrate timely performance of the approved reclamation activities for existing pits. To achieve that objective, the following terrace reclamation policies shall be in effect:
- On the west side of the Russian River, no new permits shall be approved until the Planning Department has determined in writing that reclamation of the Basalt, Grace Ranch and Phase 2 Pits has been performed in accordance with approved reclamation plans and schedules.
- On the east side of the Russian River, a maximum of 10 acres may be approved by the County if the applicable operator has submitted revised reclamation plans for the Wilson, Benoist, McLaughlin, and Richardson/Argonaut Pits and, if approved, begun reclamation work pursuant to the approved reclamation plans. No additional mining permits shall be approved until the reclamation plans for the existing pits have been approved and the Planning Department has determined in writing that reclamation has been performed in accordance with approved reclamation plans and schedules.
Benefits: County approval of each terrace reclamation plan requires a finding that the design features of the plan will provide the maximum public benefit consistent with the applicable post-mining use. Because of the value of this area's resources to the public and the unavoidable impact on agriculture, minimal reclamation of terrace mining sites to simply prevent hazards and impacts is not sufficient. The design and implementation features of each reclamation plan must assure the highest feasible level of production, value, or effectiveness for the applicable post-mining use.
This section describes the potential public benefits and environmental impacts of each of the allowed reclamation options and provides methods and criteria for maximizing benefits and minimizing impacts. The statement of standards is not intended to be a comprehensive or exclusive list. Reclamation plans may include other design features or methods which provide more public benefit and/or impact mitigation.
Completion: Reclamation plans for new terrace mining sites shall be designed to complete reclamation activities concurrently with the mining activities to the maximum extent feasible. Grading of final slopes and placement of soil shall take place at the end of the mining season in areas where the mining is complete. Planting of vegetation and other activities in the approved reclamation plan shall be completed within one year of the cessation of mining.
The operator shall submit an annual progress report on all activities related to the implementation of the reclamation plan. The owner or operator of an unreclaimed terrace pit shall also submit yearly cross-section profiles of the pit to indicate the depth of mining, water, and fill. Where an approved reclamation plan is later found to be infeasible by the County, a revised plan must be approved before any mining resumes on the site, and the originally approved financial assurances shall be maintained until the revised reclamation plan and new financial assurances are submitted and accepted.
Depending upon the future use specified in an approved reclamation plan, the Planning Department's determinations regarding completion of the reclamation shall be dependent upon the written approval of the following agencies:
- California Department of Fish and Game for wildlife habitat reclamation.
- Sonoma County Agricultural Commissioner for agricultural reclamation.
- Sonoma County Regional Parks Department for reclamation for public recreational use.
Wildlife Habitat: With proper design, the water and land features created by terrace mining and reclamation can be made into very productive habitat for fish, birds, and other wildlife. This use has the added benefit of restoring or replacing the many acres of riparian vegetation and natural habitat in the Middle Reach area consumed in the past by mining and agricultural uses. Where reclamation to wildlife habitat is proposed, a habitat restoration plan will be required to create and maintain conditions appropriate for species that have been historically found in the Middle Reach area. The plan shall set forth the specific types of habitat, describe how revegetation will take place, and present the other methods that will be utilized to enhance terrestrial and aquatic habitat. Reestablishing natural riparian conditions is the preferred type of wildlife habitat, particularly on sites within 1,000 feet of the Russian River.
In order to promote healthy, sustainable habitat conditions, the margins and slopes of the pit should be graded and contoured pursuant to the following standards unless the habitat restoration plan presents evidence that a different configuration is needed to achieve a desired habitat condition and the change is approved by the County following consultation with CDF&G or unless it is not feasible to grade an existing pit in the required manner. Areas above groundwater should be graded to a slope of no steeper than 3 horizontal to 1 vertical except that areas along the margin of the pit equivalent to at least 10 percent of the open water area should be graded flat to allow cottonwood and willow thickets to form on the land and/or freshwater marsh to form in the water. These zones should be from 5 feet below to 5 feet above early spring water level and should occupy all corners and coves of the water surface.
An additional area offshore equivalent to at least 10 percent of the open water area should be 5 to 15 feet below early spring water level and have some surface irregularity and changes in depth. Gravel shoals should be developed in these areas to create additional fish spawning habitat. The flat marsh/wooded thicket areas along the pit margin should drop abruptly to a depth of five feet or more in order to allow fish to keep mosquitos under control. Along other portions of the pit margin not adjacent to marsh and thicket areas, the underwater surface shall drop to 5 feet or more within 15 feet of the shore. The aquatic environment shall provide proper food, cover, temperature, oxygen and other conditions for successful fishery habitat.
All plantings of shrubs and trees should consist of native stock derived from areas along the Russian River in Sonoma County, preferably from within 5 miles of the area to be reclaimed. Reclamation plans shall specify the native species to be accommodated by the restoration Plan. The revegetation program will need to reflect the fluctuation of the groundwater table in the grading of the site and the selection and location of plant materials. The revegetation performance standards shall be considered met once the established plantings have been in place at least 5 years, and are capable of self regeneration and have met the quantified measurements for a period of two years without human intervention such as watering, weeding, fertilizing, replanting, etc. (Revised August 1, 1998 Resolution #98-1083 PLP98-0008)
ll grading and site preparation shall be timed to allow revegetation to be completed during the optimal planting season. The habitat restoration plan shall contain specific measures to incorporate the available topsoil from the site into the design as needed for vegetation survival. All slopes, benches, and berms shall be graded to the final slopes set forth in the habitat restoration plan with no more than 1 foot variation in relief. Slopes below the water level will meet the minimum standards set forth in the State Reclamation Guidelines.
The habitat restoration plan will contain provisions to control erosion of slopes and sedimentation of the pit. It will address how drainage from adjacent areas will be controlled and how all slopes will be benched, terraced, or otherwise protected. There shall be no gully wash or rill erosion allowed on graded slopes. All planting areas previously packed down by mining equipment or vehicles shall be ripped and scarified prior to resoiling or replanting.
Agricultural Uses: Reclamation of terrace mining sites to plant crops or other agricultural uses provides substantial public benefit because it avoids a significant long-term impact where proposed mining sites are currently in and designated for agricultural production. The topsoil from terrace mining sites shall therefore be used for surface treatment and reclamation to productive agricultural use of terrace mining sites. Topsoil remaining after agricultural reclamation may also be utilized to support approved reclamation to wildlife habitat or recreation. Topsoil to be used in agricultural reclamation shall be stored, protected, and treated to limit loss of nutrients and to maintain or enhance the ability to support crop production.
Where reclamation to plant crops is proposed, it shall be deemed successfully completed when the County Agricultural Commissioner determines that adequate survival and economic feasibility has been demonstrated. Achieving this standard requires that appropriate climatic conditions and an adequate water supply are available for the agricultural use and that the site drainage and the elevation of the ground surface above groundwater are both designed to prevent root damage and support the growth of a wide range of plant crops. Each reclamation plan proposing reclamation of terrace mining sites to agricultural uses shall include a business plan and analysis of economic feasibility which contains criteria for determining successful completion of the reclamation efforts. Results of previous or existing agricultural reclamation plan efforts shall be considered as part of the review of proposed reclamation plans
Shallow mining with agricultural reclamation is identified in Chapter 6 as the environmentally superior option, but it is not mandated by the 1994 ARM Plan because the amount of gravel removed would be much less than from deep pits, substantial additional land would be required to produce a given amount of gravel, this type of reclamation is not yet proven feasible in this area, not all terrace mining sites are prime agricultural land, and other post-mining uses of terrace pits also have distinct public benefits. For these reasons, shallow mining above groundwater is therefore subject to the annual and long-term acreage limitations stated earlier and will only be considered as part of a deep-pit terrace mining project on land abutting the deep pit.
Reclamation with Additional Fill: Importing of earth materials from off-site sources, including topsoil from other mining sites and the return of fine sediments from aggregate processing, may be necessary where reclamation to agriculture or other land-based use is proposed for a terrace pit which would be too deep to allow refill and reclamation by using on-site topsoil only. The combination of deep pits with imported fill permits more gravel to be removed while still allowing agricultural reclamation but also generates new concerns about fill materials from some sources affecting groundwater quality. Where a terrace mining site is reclaimed by refilling a pit with processing sediments or any fill from off-site sources, the following standards shall apply:
- No pollution or contamination of groundwater quality would occur, based on application of federal and State drinking water standards.
- The fill operation would be approved by the RWQCB.
- Environmental review would be conducted of the removal, transport, storage, and deposition of off-site earth materials used for refill.
- No significant impact could occur to the levels of nearby groundwater and wells based upon use of the MODFLOW computer model or similar model of equal or better analytical capability.
- Ponding of surface water would not occur after periods when the flood plain is inundated.
Aquaculture: The raising of fish and shellfish does not require the extensive land areas used by plant crops but is nonetheless considered to be an agricultural use by the General Plan. However, the feasibility of aquaculture in the terrace pits is not known at this time. Consequently, approval of this type of reclamation is permitted only where consistent with reclamation of adjacent pit areas and clearly demonstrated to be technically and economically feasible. Project design shall control surface drainage and groundwater flow into and out of the pits, including flood overflow from the river, to protect the aquaculture operation, water quality, natural existing fisheries, and adjacent properties. The reclamation plan must include a complete description of the related processing, storage, transportation, and other land-based features of the aquaculture operation and any non-aquacultural uses proposed. This type of reclamation will be deemed completed when the aquaculture operation has been fully operational for two years. Because aquaculture is unproven in this area, the reclamation plan must specify the contingencies and alternative uses that will be implemented if the aquaculture operation is found to be technically or economically infeasible within two years. Financial assurances provided by the operator must be sufficient to cover the costs of the contingency alternatives in the reclamation plan. If an aquacultural reclamation plan has been permitted for any terrace pit, its success must be demonstrated before a similar aquaculture project will be approved for any other site.
Water Supply: The abundant groundwater resource in the Middle Reach area is tapped by numerous agricultural wells and partially by the large wells of the Sonoma County Water Agency and Town of Windsor located adjacent to the Russian River. Because terrace reclamation has the potential to affect future groundwater flows and levels, reclamation plans must consider and avoid impacts on wells in the area. The conservative groundwater protection standards in section 7.6.2, including MODFLOW analysis, maximum area, and minimum separation, will prevent these impacts, but if additional mitigation is required for a specific reclamation plan, it may include an additional setback between the pit and the wells or transfer of ownership or control of the pit to the owner of the wells after mining.
Removal of large quantities of sand and gravel also increases the water storage capacity and the ease of access to the water resources if the pits are not refilled. This creates the opportunity to go beyond mitigation of potential impacts by using terrace pits to provide an additional water source or storage reservoir for nearby users and water systems. The County encourages creative use of such opportunities to enhance the water supply facilities and systems in the Middle Reach area. If supplying water to neighboring agricultural properties is proposed for a site, it may be appropriate to transfer the post-mining ownership of the site to the owners of those properties or to an irrigation district or other independent entity. Similarly, for pits located close to public water supply wells, reclamation plans should consider transferring post-mining ownership to the water purveyor. Before the approval of any terrace reclamation plan which proposes such a transfer of ownership or any off-site use of the water in the pit by parties other than the mining operator and site owner, all affected parties must agree in writing to the legal arrangements and water quality protection proposed in the reclamation plan. In any case, water supply development is considered as an added benefit or feature in conjunction with other post-mining uses allowed and is not considered to be a primary use or sufficient reclamation by itself.
Recreation Facilities and Activities: The water-based recreational opportunities associated with the lakes created by terrace mining and their proximity to the Russian River have long been recognized. The Regional Parks Department has previously expressed a need for and interest in public recreation facilities in this area. The Open Space map in the General Plan designates two general locations for future public parks in the terrace mining area, one west of Windsor River Road and the other near Wohler Bridge. The Open Space map also designates the Russian River as a Waterway Trail where recreational boating is to be facilitated and adjacent hiking trails can connect urban areas, parks, and the waterway.
The only recreational uses which could be allowed with a use permit by the present LIA General Plan designation and zoning in the terrace mining area are game preserves, horse stables, fishing and hunting clubs, and golf courses. Development of public recreational facilities by the County would therefore require changing the General Plan land use designation to Public / Quasi-Public and changing the zoning to PF Public Facilities as part of the approval process for a park master plan. minimize conflicts with the valley's prime vineyard operations. Recreational development of this area will depend upon close cooperation between the operator and the County Regional Parks Department. Transfer of ownership will require a written agreement specifying the responsibilities of each party.
County approval of a reclamation plan for the Kaiser South area shall consider the effects of the proposed mining, grading and reclamation on the potential for future public recreational development of the site. The Board of Supervisors shall direct the Sonoma County Regional Parks Department to prepare a needs assessment, site evaluation, and feasibility study for development of a regional park on the Kaiser plant site, McLaughlin Pit, Wilson Pit, Benoist Pit and adjacent properties, but this requirement is not intended to delay or prevent the approval of reclamation plans for mined lands and the completion of reclamation in accordance with approved reclamation plans. If a park appears feasible, a project design, financing plan, and environmental analysis and determination shall be prepared for Board review and approval. The net County costs of park-related activities shall be reimbursed by the Recreation Enhancement Program funded by the Russian River Gravel Mitigation Fund. The Regional Parks Department shall consult with nearby property owners and residents and other interested parties in public meetings during both the initial site evaluation and environmental analysis for the project.
Wastewater Storage: Several cities near the Russian River place treated sewage effluent in ponds for evaporation, filtering by the surrounding sand and gravel deposits, and further treatment by biological processes. The only site where this is done in the Middle Reach terrace mining area is the old Basalt pit used by the City of Healdsburg for many years. Monitoring thus far has not found any significant water quality impacts connected with this use. Any reclamation plan for this pit shall serve to protect and maintain the City of Healdsburg's ability to continue to use the pond for wastewater storage in accordance with applicable water quality standards. The processing sediments which have been piped into this pit may be removed to enlarge effluent storage capacity and provide fill for agricultural reclamation of other mined areas as long as the transfer of sediments meets the standards for imported fill stated above. No other terrace mining site may be used for storage or disposal of effluent from public sewage treatment systems unless the Board of Supervisors finds that the proposal is the environmentally superior alternative being considered, will meet applicable water quality standards enforced by the Regional Water Quality Control Board, and will avoid significant impacts on nearby groundwater and surface water.
Unfilled Pits: Unless previously specified in this Chapter, the following standards shall apply where a pit will not be refilled above groundwater level and will be left as open water:
The Management Plan identifies the Kaiser South terrace pit area, including the Wilson, McLaughlin and Benoist pits and Kaiser's processing plant site, as an appropriate location for future public recreation use. The site is well located to serve the region, connect with other publicly-owned lands, and, most importantly,
- The potential for levee failure and/or diversion of the river channel into the pit shall be minimized.
- No pollution or contamination of groundwater quality shall occur based upon federal and State drinking water standards.
- No significant impact shall occur to the levels of nearby groundwater and wells based upon use of the MODFLOW computer model or similar model of equal or better analytical capability.
- Sedimentation from erosion of adjacent slopes shall be minimized.
- Where human uses of a reclaimed pit are proposed, these shall be minimized in and adjacent to marsh areas and riparian habitat where wildlife is abundant.
- Final pit slopes below the water level shall not be steeper than 1 horizontal to 1 vertical.