Little Lake Valley Groundwater Management Plan
DRAFT
Date
Prepared for: City of Willits
Prepared By: LACO Associates, Inc 776 South State St., Suite 103 707-462-0222
Project No. 8509.07
advancing the quality of life for generations to come
Design Planning Engineering Geology and Geotechnical Environmental Science Signature Name Materials Testing Survey
800 515-5054 www.lacoassoicates.com Signature Name Eureka | Ukiah | Santa Rosa | Chico
LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN Public Review Draft
PREPARED FOR
CITY OF WILLITS
July 13, 2020
City of Willits Contact: Andrea Trincado, Project Manager City of Willits Engineering Department
Prepared by: LACO Associates 776 S. State St., Suite 103 Ukiah, California 95482 (707) 462-0222
LACO Project No. 8509.07
Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
TABLE OF CONTENTS 1.0 Introduction 4 1.1 Purpose of the Plan ...... 4 1.2 Background and Legal Authority for Local Groundwater Management ...... 4 1.3 Plan Components ...... 5 1.4 Plan Development Process ...... 5 1.5 Previous Studies ...... 6 2.0 Public Outreach and Involvement ...... 7 2.1 Public Opinion Survey ...... 8 2.2 Public Workshops ...... 8 2.3 Issues of Concern to the Public ...... 9 3.0 Study Area 9 3.1 Location and Description ...... 9 3.2 Physical Geography and Geology ...... 9 3.2.1 Geologic Formations ...... 10 3.3 Climate 11 3.4 Land Use and Population ...... 11 3.5 Water Use 12 3.5.1 Municipal Water Use ...... 12 3.5.2 Rural Water Use ...... 13 3.5.3 Tribal Water Use ...... 13 3.5.4 Environmental Water Use ...... 13 4.0 Hydrogeology 14 4.1 Principal Aquifers ...... 14 4.1.1 Aquifer I – Holocene Alluvium ...... 14 4.1.2 Aquifer II – Pliocene to Pleistocene Continental Basin Deposits ...... 16 4.1.3 Jurassic-Cretaceous Franciscan Complex .. 16
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4.2 Historic Variations in Groundwater Levels ...... 17 4.3 Historic Groundwater Pumpage ...... 19 4.4 Groundwater Recharge ...... 19 5.0 Surface Water Hydrology ...... 20 5.1 Surface Water Systems and Waterbodies ...... 20 5.1.1 Streams 21 5.1.2 Little Lake ...... 21 5.1.3 Surface Water Facilities ...... 21 5.2 Surface Water Quality ...... 22 5.2.1 Naturally Occurring ...... 22 5.2.2 Point Source Impacts ...... 23 5.2.3 Non-Point Source Impacts ...... 23 6.0 Components of the Groundwater Management Plan ..... 24 6.1 Goals and Objectives ...... 24 6.1.1 Groundwater Management Goals ...... 24 6.1.2 Basin Management Objectives ...... 24 6.2 Groundwater Monitoring ...... 25 6.2.1 Monitoring of Groundwater Levels and Storage 25 6.2.2 Monitoring of Groundwater Quality ...... 26 6.2.3 Inelastic Land Subsidence Monitoring ...... 26 6.3 Groundwater Resource Protection ...... 27 6.3.1 Control of Saline Intrusion ...... 27 6.3.2 Wellhead Protection and Recharge Area Protection ...... 27 6.3.3 Administration of Well Abandonment and Well Destruction Program ...... 28 6.3.4 Well Construction Policies ...... 28 6.3.5 Construction and Operation of Groundwater Projects 29
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6.3.6 Mitigation of Conditions of Overdraft ..... 29 6.3.7 Replenishment of Groundwater Extracted by Water Producers ...... 29 6.4 Groundwater Management Coordination ...... 29 6.4.1 Facilitate Conjunctive Use Operations ..... 30 6.4.2 Relationships with Local, State, and Federal Entities 32 6.4.3 Review and Coordination of Land Use Issues 32 7.0 Groundwater Management Plan Implementation and Financing 33 7.1 Plan Implementation ...... 33 7.2 Plan Financing 34 8.0 References 35 Figures 39 Appendix A 51 Appendix B 54 Appendix C 57
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1.0 INTRODUCTION This Little Lake Valley Groundwater Management Plan (GWMP) represents the initial effort on the part of the City of Willits (City) to develop a plan for sustainable management of groundwater in the Little Lake Valley. This GWMP seeks to provide a framework for advancing the level of understanding and coordinating the management of groundwater resources in the Little Lake Valley.
This voluntary, non-regulatory GWMP identifies a range of local groundwater management actions to sustain groundwater resources into the future. This GWMP is intended to provide guidance for groundwater management throughout the Little Lake Valley; however, the City recognizes that City’s authority to take any recommended actions is only valid within the jurisdictional boundaries of the City of Willits. The boundaries of the Little Lake Valley Groundwater Basin (the Basin) and the portion of the Basin covered by this GWMP are shown on Figure 1-1.
1.1 Purpose of the Plan The purpose of this GWMP is to provide a framework for monitoring, analyzing, and interpreting Basin characteristics and identifying for implementation effective management practices to utilize and protect valuable groundwater resources within the Basin. The GWMP serves to improve the understanding and management of the groundwater resources in the Little Lake Valley, providing preliminary guidelines and recommendations for the City of Willits and other water users to implement effective and sustainable groundwater management programs. The GWMP will provide guidance on managing the groundwater resources of the City of Willits and documenting objectives for proper management of the Basin, where mismanagement can impact residents and business owners within the City Limits along with those that live and/or work outside of the City Limits in the valley and surrounding hills. The GWMP documents groundwater conditions, management goals and objectives, and proposed implementation activities to achieve the GWMP purpose. In addition, the GWMP will allow for the City of Willits and some other stakeholders within the Basin to be eligible for grant funding administered through the Department of Water Resources (DWR) for projects related to groundwater.
1.2 Background and Legal Authority for Local Groundwater Management In early 2019, the City of Willits submitted a preliminary grant application for Integrated Regional Water Management (IRWM) funding, administered by the DWR for a groundwater supply project which would greatly improve drinking water supply reliability for the community, especially in times of drought. The project was selected for funding; however, as outlined in the IRWM Grant Program Guidelines (2019), as a condition for receiving the funding, the City of Willits must commit to adopting a groundwater management plan that meets the requirements of Water Code §10753.7 by September 6, 2020 (within one year of the final grant application submittal date of September 6, 2019). On December 11, 2019, the City of Willits City Council formally approved Resolution No. 2019-59 noticing its intent to prepare a groundwater management plan for the Little Lake Valley groundwater basin not covered by another groundwater management plan (resolution of intention). The resolution of intention is included as Appendix A.
The development of a groundwater management plan is governed by the Groundwater Management Act, which was codified into law in 1992 as California Water Code (CWC) §10750 et seq. and was subsequently amended in 2002 and 2011. CWC §10750 et seq. allows development of a groundwater management plan by local agencies to efficiently manage and maximize groundwater supplies, assure long term water
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supplies, and distribute costs, benefits, and water sharing in an equitable manner. The City of Willits is an authorized groundwater management agency as defined in Water Code § 10753 (a). Adoption and implementation of this GWMP by the City of Willits will not affect the authority of other local agencies within the Basin to implement their own groundwater management plans, nor will it affect the management of groundwater outside the jurisdiction of the City of Willits. However, it would be in the best interest of the water users of the Basin to have coordinated goals and strategies for sustainable management of the Basin. Though there are no other water purveying local agencies currently within the Basin, as shown on Figure 1-2, the City of Willits encourages all future groundwater purveyors and existing and future water users to participate in the implementation of and future updates to this GWMP. Local agencies that adopt a water purveying role in the future and do not have their own groundwater management plans may adopt this GWMP by resolution, if they choose, and execute a Memorandum of Understanding (MOU) with the City of Willits for cooperation and joint implementation of the GWMP.
1.3 Plan Components In 1992, the California Legislature introduced the California Groundwater Management Act as Assembly Bill 3030 (AB 3030) to encourage local public agencies to adopt plans to manage groundwater resources within their jurisdictions. Provisions were created in the CWC § 10750 et. seq. to manage the safe production, quality, and proper storage of groundwater. In 2002, Senate Bill 1938 (SB 1938) was signed into law, amending the California Groundwater Management Act by requiring any public agency seeking State funds administered through DWR for the construction of groundwater projects to prepare and implement a GWMP with specified required components, and adding 12 voluntary components for a GWMP. In 2003, DWR published Bulletin 118 – Update 2003, California’s Groundwater, which includes a list of components recommended to be included in a groundwater management plan. The California Groundwater Management Act was again modified in 2011 through Assembly Bill 359 (AB 359), which added an additional required component for GWMPs, focusing on identifying groundwater recharge areas, and made several procedural changes for plan adoption.
This GWMP prepared by the City is a stand-alone document that meets the requirements set by SB 1938 and includes the applicable voluntary and recommended components codified by AB 3030 and AB 359 and recommended in Bulletin 118-2003. A summary table is enclosed as Appendix B listing each required, recommended, or voluntary component and where to find those components in the document. For recommended or voluntary components which were not included in the GWMP, a brief explanation is also provided in Appendix B.
1.4 Plan Development Process The GWMP was developed in accordance with the requirements of CWC § 10753.2 through 10753.6, as described below.
Step 1 – Provide public notification of and subsequently complete a hearing on whether or not to adopt a resolution of intention to draft a GWMP. Following the hearing, draft a resolution of intention to draft a GWMP.
On December 11, 2019, the City of Willits City Council held a public hearing, noticed pursuant to § 6066 of the Government Code, on whether or not to adopt a resolution of intention to draft a GWMP.
Step 2 – Adopt a resolution of intention to draft a GWMP and publish the resolution of intention in accordance with public notification.
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The City of Willits City Council adopted the resolution of intention to draft a GWMP on December 11, 2019. The adopted resolution is included in Appendix A.
Step 3 - Prepare a draft GWMP within two years of resolution of intention adoption. Provide to the public a written statement describing the manner in which interested parties may participate in developing the GWMP.
The City of Willits provided notification on its website, has held two public meetings where meeting attendees were able to give input on the GWMP. The City of Willits intends to hold one additional public meeting before completing the final draft. The public draft of the GWMP will be made available to the public upon completion. While CWC § 10753.4 requires that a groundwater management plan be adopted within two years of the date of adoption of the resolution of intention, as described above, per the Guidelines of the 2019 IRWM Grant Program under which the City of Willits has applied for funding for a groundwater supply project, the City of Willits must adopt a groundwater management plan by September 6, 2020 (within one year of the final grant application submittal date of September 6, 2019).
Step 4 – Provide public notification of a hearing on whether or not to adopt the GWMP, followed by holding a hearing on whether or not to adopt the GWMP.
The City of Willits anticipates holding this hearing in August 2020.
Step 5 – The plan may be adopted within 35 days after the completion of Step 4 above if protests are received for less than 50 percent of the assessed value of property in the plan area. If protests are received for greater than 50 percent of the assessed value of the property in the plan area, the plan will not be adopted.
The City of Willits seeks to adopt the GWMP following hearing described in Step 4, above.
1.5 Previous Studies While numerous studies related to groundwater have been previously prepared for the Little Lake Valley, this GWMP is the first groundwater management plan, as defined in CWC § 10750 et. seq., to be prepared for the Basin. The primary reason being the very low priority designation assigned to the Basin by the DWR. Previous studies of note, and referenced in this GWMP, include, but are not limited to:
Geology and Ground Water in Russian River Valley Areas and in Round, Laytonville and Little Lake Valleys Sonoma and Mendocino Counties, California (1965) – prepared by G.T. Cardwell of the U.S. Geological Survey, in cooperation with the California Department of Water Resources, dated 1965.
This report was prepared to provide fundamental geologic and hydrologic information about 10 valleys in Sonoma and Mendocino Counties in California. The work in Mendocino County was initiated to determine a basis for setting up well construction standards in the county and supplemented previous work by the California Department of Water Resources.
Ground-Water Resources in Mendocino County, California (July 1986) – prepared by C.D. Farrar of the U.S. Geological Survey, in conjunction with the California Department of Water Resources and Mendocino County.
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Ground-Water Resources in Mendocino County, California was prepared to better understand the ground- water resources of Mendocino County, with a focus on individually specific high-interest areas including Ukiah, Little Lake, and Laytonville Valleys, and the Leggett area.
Ground water study (August 5, 1987) – prepared by the California Department of Water Resources (DWR), Northern District, in cooperation with the City of Willits.
The 1987 ground water study was prepared to provide the City of Willits with information on the availability, occurrence, quantity and quality of ground water to enable it the City of Willits to decide on how to meet present and future water needs.
Water Supply Planning Study (February 2006) – prepared by West Yost & Associates for the City of Willits.
This Water Supply Planning Study was prepared, on behalf of the City of Willits, to analyze the City of Willits water demands and existing water supply capacity and to determine any need for a supplemental water supply.
2.0 PUBLIC OUTREACH AND INVOLVEMENT The City of Willits developed and implemented a Public Outreach Plan, dated January 2020 and included in Appendix C, to support and inform the development of the GWMP and guide the inclusion of local stakeholders in the process. In addition to the statutory requirements of the CWC, the City of Willits made additional efforts to involve the public in the development of the GWMP.
The Public Outreach Plan identified the following objectives for public outreach: Inform the public regarding the process for – and progress of – GWMP development; Consult with interested stakeholders and the general public throughout the GWMP development process; Involve stakeholders in determining the planning goals and objectives; Collaborate with stakeholders to include their recommendations and concerns, where feasible; and Empower the water users and managers of the Little Lake Valley Groundwater Basin to develop a sustainable and manageable GWMP for the future.
It should be noted that the Public Outreach Plan included in Appendix C was drafted in January 2020 prior to the onset of the COVID-19 pandemic and the subsequent Shelter-in-Place order in effect in Mendocino County beginning in March 2020. Due to the Shelter-in-Place orders, limitations on available City of Willits staff time and resources, and As such, the planned outreach methods and timelines provided in the Public Outreach Plan do not necessarily reflect the outreach methods that the City of Willits has been able to complete and a modified timeline on the development of this GWMP public review draft, the City of Willits has explored and continues to explore alternative options for public outreach. In addition, the City of Willits intends to include a revised version of the Public Outreach Plan in the final Draft of the GWMP that more accurately reflects the actual GWMP development process.
Implementation of the Public Outreach Plan, to date, has included public notification and interaction with the public through the following outreach methods:
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Table 2-1. Summary of Public Outreach Methods Method Description Press Releases Provided written information to local newspapers for publication. Maintenance of a list of individuals and organizations with interest in the Email List GWMP, with those individuals and organizations receiving updates on the GWMP progress and notifications of upcoming events. A section of the Public Works (Water) webpage was dedicated to the GWMP as a means to disseminate information on the GWMP via the Internet. This also provided a manner for the City of Willits to make available to the public a Website written statement describing the manner in which interested parties may participate in developing the groundwater management plan, in accordance with CWC § 10753.4(b). The City of Willits created a Public Opinion Survey to solicit public input on current and historic observations of groundwater use in the Little Lake Valley. Respondents were asked questions related to their water source, groundwater Survey use, groundwater concerns, water quantity, and water quality. Hard copies and an electronic survey were made available to the public. The Survey and summarized results are included in Appendix C. The City of Willits has held two public workshops thus far. The workshops were open to the public and included opportunities for the public to ask questions of the planning team and to offer suggestions, either at the meeting or Public Workshops thereafter. The City of Willits intends to hold an additional public workshop following release of this Public Review Draft. Additional detail provided in Section 2.2, below. Prepare and conduct two public hearings: one to adopt the resolution of intention to draft the GWMP; and one to adopt the final GWMP. The first public Public Hearings hearing was held on December 11, 2019. The City of Willits anticipates holding the second hearing in August 2020.
2.1 Public Workshops As noted above, as of the date of this Public Review Draft GWMP, implementation of the Public Outreach Plan has included two public workshops: a targeted stakeholder workshop was held on February 13, 2020, followed by a public workshop on February 20, 2020. These two workshops were hosted as open forums during which the City of Willits, with the support of LACO Associates (LACO), provided a brief overview of the GWMP and received input on groundwater management in the Little Lake Valley in general. The presentations from each workshop are included in Appendix C.
While both workshops were open to the public, the targeted stakeholder workshop was intended to involve primarily local public agencies with lands overlying the Basin, public water purveyors in the area surrounding the Little Lake Valley, environmental stakeholders, and individuals with contractual water-sharing agreements with the City of Willits. The targeted stakeholder workshop was attended by seven (7) individuals representing both public and private interests. The public workshop was attended by four (4) members of the public with private wells and/or general interest in groundwater use in the Basin.
The City intends to hold an additional public workshop in mid-July 2020, following release of this Public Review Draft of the GWMP; however, as noted above, due to the Shelter-in-Place orders in affect in Mendocino County beginning in March 2020, in response to the COVD-19 pandemic, limitations on available City of Willits staff time and resources, and the timeline on the development of the GWMP public review draft, the final public workshop may not be possible in the manner proposed in the January 2020 Public Outreach Plan. All
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individuals interested in continuing to participate in the development of the GWMP will be encouraged to review the Public Review Draft of the GWMP and provide written comments to the City of Willits for its consideration when drafting the final Draft of the GWMP.
2.2 Issues of Concern to the Public The most common concern expressed by the public in both the Survey and public workshops was related to overdrafting of the groundwater basin leading to shortages in water availability or negative changes to water quality for property owners who rely on wells in the Basin for their domestic water source. According to a few respondents and workshop attendees, the static groundwater level, particularly in shallow wells, has lowered in recent years.
3.0 STUDY AREA The following section serves to demonstrate the current understanding of the Basin as a whole, and the area of the Basin to be managed through implementation of this GWMP.
3.1 Location and Description The Little Lake Valley is located in central Mendocino County (County), approximately 140 miles north of San Francisco and 25 miles north of Ukiah, and approximately 3 miles north of the drainage divide between the Eel River and Russian River drainage basins. The Basin has a total surface area of 11,520 acres, or 18 square miles, has an oblong-shaped flat floor that is approximately 7 miles in length measured north to south, and up to 3 miles wide measured east to west at the widest point in the valley (DWR, 2004).
The City of Willits, with a total incorporated area of 2.8 square miles, occupies the western periphery of the Basin, as shown on Figure 1-1. Environmental conditions within the City of Willits are reflective of Willits’ history as a subregional commercial and industrial center. Although past development altered the natural environment within the city limits, the City of Willits retains a small-town character, which is reflected in the design of its residences, commercial buildings, and public open space (General Plan, 1992).
3.2 Physical Geography and Geology Little Lake Valley is an intermontane basin located within the Central Belt of the Franciscan Complex at an elevation of approximately 1,300 feet above mean sea level (Erickson, 2008). The valley fill dips uniformly to the north with a mean dip of 8 degrees north (Woolace, 2005). Slopes on the western side of the valley are susceptible to landslides. They range between 7 and 12 degrees, have a peak elevation of approximately 2,600 feet above mean sea level, and consist of a mélange of greywacke and chert. Slopes on the eastern side of the valley are more competent. They range between 10 and 25 degrees, have a peak elevation of approximately 2,800 feet above mean sea level, and consist of the metavolcanics of Rocktree Valley and the heavily fractured greywacke of Berry Canyon (Erickson, 2008). .
As shown on Figure 3-1, several small creeks flow through the Little Lake Valley, including Baechtel Creek, Broaddus Creek, Davis Creek, Haehl Creek and Willits Creek. The creeks generally flow north until they converge at the north end of the Little Lake Valley in a poorly drained, marshy area to form Outlet Creek, a tributary of the Eel River (Farrar, 1986). Little Lake Valley drains into the Eel River to the north; however, clasts in Pleistocene gravels indicate that the Little Lake Valley historically drained south into the Russian River (Woolace, 2005). Evidence that the Little Lake Valley once drained to the Russian River was first presented
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by Cardwell (1965), who used well logs to infer widespread fluvial and lacustrine deposits in both Little Lake Valley and Upper Russian River Valley. Additional evidence has been presented by Woolace (2005) for fluvial connectivity through similarities between sediment and stratigraphy based on field reconnaissance and well logs. Sediments and stratigraphy were classified through texture, clast size, degree of weathering, frequency and distribution of deposits, and clast lithology (Woolace, 2005).
Little Lake Valley is in the California Coast Ranges Geomorphic Province. This province is seismically active and geologically complex due to historic and ongoing tectonic deformation that is characterized by northwest-trending faults and topographic and geologic features. The complex structure of the Coast Ranges Geomorphic Province began with a period of plate convergence during late Jurassic which involved eastward thrusting of the oceanic crust beneath the coastal crust and was characterized by the accretion of material to the continent and the formation of east-dipping thrust and reverse faults. Beginning in the mid- Cenozoic and continuing to the present, the plate boundary was dominated by right-lateral, strike-slip deformation which was superimposed on the existing structures. This is characterized by the northwest- trending nearly vertical faults of the San Andreas system.
Numerous active faults traverse the Little Lake Valley and have the potential to generate strong ground shaking. The valley was presumably formed by faulting of the Maacama fault zone in the southwest and northeast margins of the valley, and later altered by erosion (North Coast Hydrologic Region, 2004). The right lateral Maacama fault, considered an active fault by the California Geological Survey (CGS), runs through the City of Willits and has a slip rate estimated at 5 millimeters per year (Woolace, 2005). Other major active faults in the surrounding region are the San Andreas fault and the Bartlett Springs fault (City of Willits, 2019). The basin strata of Little Lake Valley tilt northward due to a regional extensional response to the northward passage of the Mendocino Triple Junction. Northward tilt of the basin strata and land subsidence occurs along the East Valley Fault and North Valley Fault (Woolace, 2005). The East Valley Fault Zone is Holocene active, but slip has not propagated to the ground surface (Erickson, 2008).
3.2.1 Geologic Formations The valley fill in Little Lake Valley is composed of Holocene deposits and older Pliocene to Pleistocene continental basin deposits, which overlie the Jurassic-Cretaceous Franciscan Complex. Valley fill ranges in thickness; gravity models suggest that the fill thickens from approximately 820 feet in the northern portion of the valley to approximately 3,280 feet in the southern portion of the valley (Erickson, 2008). The basin boundary is defined by the contact between the Holocene alluvium or Pliocene to Pleistocene continental basin deposits, and the Franciscan Complex (Farrar, 1986). The geology of the Little Lake Valley is depicted in Figure 3-2 and Figure 3-3, as presented by Woolace (2005).
Holocene Deposits - Alluvial, Colluvial, and Lacustrine Deposits Holocene alluvial, colluvial, and lacustrine deposits overlie the continental basin deposits and cover most of the valley, with an area of approximately 13 square miles (Farrar, 1986). The Holocene deposits were derived from erosion of the surrounding mountains and the continental basin deposits in the southern part of Little Lake Valley. The deposits consist of gravel, sand, silt, and clay (Farrar, 1986). Holocene deposits range in thickness but thicken to the north. At the southern portion of Little Lake Valley, they are absent, but at the northern part of the valley, they have a thickness of approximately 100 feet (Woolace, 2005; Erickson, 2008).
Pliocene to Pleistocene Continental Basin Deposits Continental basin deposits are widespread and are exposed discontinuously along a five square mile area in the southern part of Little Lake Valley (Farrar, 1986). The deposits outcrop as uplifted, eroded valley fill, and
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form low lying hills (Woolace, 2005) comprising poorly sorted gravel, sand, silt and clay; and interbedded with low permeability clays. Individual bed thicknesses range from less than 1 foot to more than 100 feet (Farrar, 1986). In the central and northern parts of Little Lake Valley the continental basin deposits are buried by Holocene alluvium, and in the central part of the valley it has been observed in incised stream banks (Woolace, 2005). The deposits range in thickness and based on post-depositional tilting in the southern portion of the valley, the deposits have been inferred to have a thickness up to approximately 3,600 feet in the northern part of Little Lake Valley (Woolace, 2005).
Jurassic-Cretaceous Franciscan Complex Franciscan Complex rocks are primarily meta-sedimentary rocks that were deposited in a marine environment and underwent stress and deformation from compressional tectonism. The bulk of the Franciscan Complex is composed of sandstone and mudstone with local bodies of serpentinite, greenstone, schist, shale, chert, limestone, and mafic igneous rocks (Farrar, 1986). Gravity models suggest that the Franciscan Complex bedrock is deepest in the southern portion of the valley. Gravity models also suggest that in contrast to the north dipping valley fill, the basement floor slopes towards the south (Erickson, 2005).
3.3 Climate The Little Lake Valley is characterized by a Mediterranean climate with hot, dry summers and cool, rainy winters. The local climate is strongly influenced by its topographic setting as it is subject to both maritime and interior influences. The hills along the west side of the Little Lake Valley both moderate the maritime influence of the ocean and block much of the summer sea fog from reaching the valley. Cold air drainage from surrounding higher elevations is heavy during the winter and spring months (General Plan, 1992).
Rainfall occurs mainly between October and May and averages approximately 51.9 inches annually (City of Willits, 2019). Temperatures vary from a low of 14 degrees Fahrenheit (°F) in January to a maximum of 108 °F in July (General Plan, 1992), with an annual average (between 1961 and 1990) of 69.4 °F (City of Willits, 2019). Based on wind data provided in the 2012 Harris Quarry Final EIR, the average annual wind speed in the City of Willits for all times of the day is approximately 5.1 miles per hour (mph), with an average wind speed during daytime hours of 6.6 mph, and a maximum wind speed of 19.2 mph. Prevailing winds are generally from either the northwest or southeast (General Plan, 1992).
3.4 Land Use and Population Timber and agriculture were the mainstays of the County’s economy from the 19th Century into the 20th, and in the 21st Century continue to remain important to both the economy and culture of Mendocino County, although the character of agriculture is changing. The County’s timber industry faces increasing competition from worldwide sources of lumber that have made it difficult for local mills to remain competitive. The County’s agricultural industry is seeing a shift from historic crops such as pears, apples, prunes, and livestock, to grapes and wine making, and cannabis in some areas of the County.
Much of the development in the Little Lake Valley is located along U.S. Highway 101 and State Route 20 within the City of Willits and served by city-provided utilities. The majority of lands within the Little Lake Valley and outside the city limits are used for agricultural, rangeland, and residential purposes see Figure 3-4 and Figure 3-5. Agricultural lands within the Little Lake Valley and the foothills west of the City of Willits are primarily utilized as open space or for the production of hay and livestock, most commonly sheep, cattle, and horses. The amount of land within and at the periphery of the Little Lake Valley utilized for the cultivation of cannabis is currently unknown; however, the number of cannabis farms in the Little Lake Valley has continued to grow
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with the implementation of the Mendocino Cannabis Cultivation Ordinance, adopted April 4, 2017. Within the City of Willits, which comprises 2.8 square miles of the 18 square miles of the Little Lake Valley, land uses are primarily designated as residential, commercial, and industrial use, with open space, public facilities, and roadways comprising the remainder.
Based on the U.S. Census Bureau Quick Facts, Mendocino County had a population of approximately 86,749 persons as of July 1, 2019, a decrease of approximately 1.3 percent since April 1, 2010. Based on 5-year estimates from the 2018 American Community Survey of the U.S. Census Bureau, the City of Willits had a population of 4,893 persons. Approximately 5.6 percent of the persons living in Mendocino County reside in the City of Willits, based on the aforementioned estimates. The majority of the population outside the City resides in the approximately 6,000-lot Brooktrails Township development northwest of the City of Willits, and the Pine Mountain Estates development located southeast of the City of Willits, on the periphery of the Little Lake Valley. It should be noted that the Water Supply Planning Study prepared by West Yost Associates in 2006 predicted that the population of the City of Willits would increase from roughly 5,000 people in 2000 to approximately 7,000 in 2020. Based on the recent population estimates provided above, the projected population growth has not been realized.
The County of Mendocino, the City of Willits, and the Brooktrails Township Community Services District (Brooktrails) are the jurisdictions responsible for preparing land use planning documents and making decisions that affect land use in and around the project area. Land use planning activities in the unincorporated area outside the City of Willits city limits and within the City of Willits are directed by their respective General Plans, while a Specific Plan is the guiding document for development in Brooktrails. These Plans jointly lay out blueprints for the physical, economic, and social development of the area.
3.5 Water Use DWR has recorded well completion reports for approximately 544 wells in the Little Lake Valley. According to DWR, these wells are used for municipal, domestic, agricultural, industrial, monitoring, vapor extraction, test well, and unspecified purposes. Approximately 270 of the 544 wells are located within the City of Willits, and the remaining wells are in the north and northeast portion of Little Lake Valley. The number of wells by well use, as defined by DWR, are listed in Table 3-1, below, and the approximate locations of the wells are presented in Figure 3-6.
Table 3-1. Number of Wells Recorded by DWR by Well Use Well Use Number of Wells Municipal 4 Domestic 115 Agricultural 16 Industrial 4 Monitoring 71 Vapor Extraction 7 Test Wells 3 Unspecified 324
3.5.1 Municipal Water Use The City of Willits is the only water purveyor within the Little Lake Valley. As of 2019, the City of Willits water system served approximately 5,500 to 6,600 people in the City of Willits and surrounding areas, with approximately 2,500 residential and commercial connections. From 2013 to 2018, the City of Willits provided
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an average of 300 million gallons per year (Mgy), or 920 acre-feet, of treated drinking water, with an average of 0.822 million gallons per day (Mgd), and peak flows up to 1.369 Mgd in summer (LACO, 2019).
Until recently, all water for the City of Willits water system was supplied from surface water reservoirs in the Lower Davis Creek watershed: the Morris Reservoir and the upstream Centennial Reservoir. Water from these sources is treated at the surface water treatment plant located near Morris Reservoir and piped to the City of Willits and surrounding areas approximately 2.5 miles via a single transmission line. In response to the severe drought conditions in 2013-2014, the City was forced to construct a groundwater treatment plant and develop two additional wells to offset surface water usage. The first well, Elias Replacement well, was put into service in late 2014 after being approved by the Division of Drinking Water as a public water source. The groundwater treatment plant was designed to take and treat raw water from three different wells with mixing to dilute constituents of concern and allow for treatment to meet California drinking water standards. The City is in the process of bringing the Long 20 Test well into service and expects that second well will likely be sufficient to meet current surface water offset goals. The City of Willits intends to increase their groundwater pumping capacity to improve water system resiliency and reliability during times of drought or other disaster. This conjunctive use operation is described in more detail in Section 6.4.1, below.
3.5.2 Rural Water Use Rural water users include agricultural land owners/ranchers and rural domestic users. Water for agricultural uses, including crop cultivation and ranching, is primarily sourced from local groundwater, with a small quantity of water sourced from recycled water from the City of Willits wastewater treatment plant and local surface water (as discussed in Section 5.0). Rural domestic water users in the Little Lake Valley located outside the boundaries of the City of Willits water supply system primarily utilize domestic groundwater wells for their water sources.
As noted above, much of the population of the Little Lake Valley lives outside the City of Willits city limits in the communities of the Brooktrails Township and Pine Mountain Estates. These communities rely on surface water sources to serve the residents: Lake Emily and Lake Ada Rose through the Brooktrails Township Community Services District, and the Chinquapin Reservoir through the Pine Mountain Mutual Water Company, respectively.
3.5.3 Tribal Water Use As shown on Figure 1-2, portions of the Sherwood Valley Rancheria are located on the eastern and western peripheries of the Basin. The lands on the west side of the Little Lake Valley are served by the City of Willits water supply system, while the lands on the east side of the Little Lake Valley are served by private wells.
3.5.4 Environmental Water Use Since 2015, Caltrans has utilized groundwater from the Basin to construct and maintain wetlands in the northern portion of the Basin in order to mitigate for impacts to the Little Lake Valley caused by construction of the Willits Bypass, which was completed in November 2016. The Caltrans mitigation wetlands used an estimated 979,000 gallons of groundwater per season during construction. In addition to the groundwater used to establish the mitigation wetlands, continued cattle grazing on designated portions of the mitigation lands utilizes approximately 2.5 million gallons (7.7 acre-feet) of groundwater per dry season (Personal Communication, Mendocino County Resource Conservation District, June 2020).
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4.0 HYDROGEOLOGY
4.1 Principal Aquifers Two principal aquifers are identified in the Little Lake Valley Groundwater Basin: Aquifer I – Holocene deposits; and Aquifer II – continental basin deposits. In addition to the two principal aquifers, groundwater also occurs in the fractures of the Franciscan Complex. This section describes the physical properties and water quality of each principal aquifer, and the Franciscan Complex.
4.1.1 Aquifer I – Holocene Alluvium Aquifer I consists of Holocene alluvial deposits and is the primary hydrogeologic unit for groundwater supply in the Basin. Summaries of the physical properties and groundwater quality of Aquifer I are discussed below.
Aquifer I - Physical Properties Aquifer I is generally an unconfined aquifer but has areas of local confinement and is the most productive aquifer in Little Lake Valley. The lateral extent of Aquifer I is consistent with the mapped geologic extent of Holocene alluvial deposits, see Figure 3-2 and Figure 3-3. Coarser sediments of the Holocene alluvium were deposited as lenticular bodies on alluvial fans and river channel deposits of Outlet Creek and several smaller streams that flow north through the valley and include Baechtel Creek, Broaddus Creek, Davis Creek, Haehl Creek and Mill Creek. Finer sediments were deposited around lakes and floodplains (Cardwell, 1965). Floodplains occur in a large marshy area at the northern extent of the valley. During some winter seasons, the large marshy area in the northern extent of the valley forms Little Lake, a shallow lake that spans several hundred acres (Farrar, 1986). A flood insurance rate map displaying the lateral extent of floodplains delineated by the Federal Emergency Management Agency (FEMA) is presented in Figure 4-1. The vertical extent of Aquifer I is defined by the thickness of the Holocene alluvium, which varies across the Little Lake Valley and thickens to the north. At the southern portion of the valley, continental basin deposits crop out and the Holocene alluvium is absent in those locations. At the northern part of the valley, the Holocene alluvium has a thickness of approximately 100 feet (Woolace, 2005; Erickson, 2008)
Holocene alluvial deposits are high in both porosity and permeability and, therefore, have high yields, capable of providing sufficient water for irrigation and municipal use. In some areas, wells can produce up to 1,000 gallons per minute (gpm). However, most wells in the Holocene alluvium are only 50 to 100 feet deep and yield an average of 20 gpm. Specific capacities are relatively high; data indicate specific capacities range between 0.3 and 83 gallons per minute per foot (gpm/ft), with a mean of 2.75 gpm/ft (Farrar, 1986). Physical properties including well yield, specific yield, specific capacity, and groundwater storage capacity are summarized in Table 4-1 below. Table 4-1. Physical Properties of Aquifer I Physical Property Value Source Average 20 gpm Farrar (1986) Well Yield Max 1,000 gpm North Coast Hydrologic Specific Yield 8 percent Region (2004) 0.3- to 83- gpm/ft Farrar (1986) Specific capacity Mean of 2.75- gpm/ft Cardwell (1965) 35,000- to 90,000-acre Groundwater storage capacity DWR (1965) feet Farrar (1986)
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Aquifer I – Water Quality In general, the groundwater quality in the Holocene alluvial deposits is characterized mainly as bicarbonate type in which calcium, magnesium, and bicarbonate are predominant and chloride and sodium are minor. However, there are exceptions in which sodium and chloride are predominant and dissolved-solids concentrations are elevated in respect to the calcium- magnesium bicarbonate water type (Cardwell, 1965). Deeper wells in the alluvium contain approximately equal proportions of calcium, magnesium, and sodium. Water in shallower wells in the alluvium contain less sodium than deeper alluvial wells (Cardwell, 1965). Concentrations of iron and manganese are generally high, while concentrations of chloride and sulfate are generally low and concentrations of boron and sodium are generally not present in objectionable concentrations (Cardwell, 1965). The chemical properties presented by Cardwell (1965) are summarized in Table 4-2, below. However, it should be noted that these values do not clearly distinguish between Aquifer I and Aquifer II.
Table 4-2. Chemical Properties of Groundwater in the Basin Constituent or Characteristic Value Dissolved solids 70 to 522 ppm
Hardness (CaCO3) 3 to 326 ppm Chloride 3 to 62 ppm Percent sodium 11 to 34 percent Boron 0.4 to 3.8 ppm Iron 0.2 to 9.6 ppm pH 6.4 to 7.3 Temperature 57 to 60 degrees Fahrenheit
Groundwater in Aquifer I is impaired by high concentrations of iron, manganese, chloride, boron, and arsenic (DWR, 2003; Cardwell, 1965; Farrar, 1986; West Yost, 2006). The reported concentrations of iron, manganese and chloride generally exceed EPA secondary standards for drinking water. EPA secondary standards are non-enforceable guidelines regulating contaminants that may cause cosmetic or aesthetic effects rather than detrimental health effects.
Farrar (1986) analyzed 20 samples collected from throughout the basin and reported boron concentrations Basin ranging between 20 and 127,000 micrograms per liter (μg/L), with higher concentrations identified in the northern part of the Basin. In four (4) of the 20 samples analyzed from wells located in the north and northeastern portions of the valley, boron concentrations exceeded 2,000 μg/L. There is no EPA standard for boron; however, it is known to have adverse effects on plants at high concentrations, and according to Farrar (1986), boron concentrations exceeding 1,000 μg/L are not acceptable for agricultural uses.
Elevated levels of arsenic exceeding EPA standards have been found in the City’s Park well and the Long 20 Test well (DWR, 1987; LACO, 2018). However, the Long 20 Test well is significantly lower than the Park well. The zone testing for the Long 20 Test well showed the arsenic concentration increasing with depth with the lowest concentration in the upper zones of 0.016 mg/L and the highest concentration in the lower zone of 0.21 mg/L. Whereas, the Elias Replacement well, which is approximately 2,500 feet away from the Long 20 Test well, zone testing showed no detectable arsenic concentration at any depth (GHD, 2015). In addition to arsenic, the Park well water quality tests show high levels of hardness, iron, manganese, and turbidity; and the Long 20 Test well water quality tests showed elevated levels of barium iron, manganese, odor, color, and turbidity (West Yost & Associates, 2006; LACO, 2018).
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4.1.2 Aquifer II – Pliocene to Pleistocene Continental Basin Deposits Aquifer II consists of Pliocene to Pleistocene continental basin deposits and is semi-confined to confined with lower yields than Aquifer I. Summaries of the physical properties and groundwater quality of Aquifer II are discussed below.
Aquifer II - Physical Properties Aquifer II is a semi-confined to confined aquifer that underlies the Holocene alluvium deposits of Aquifer I. Continental basin deposits crop out in the southern half of Little Lake Valley and the geologic extent of the outcrop is mapped in Figure 3-2 and Figure 3-3. The outcrop forms discontinuous foothills on the valley floor and strata indicate an anticlinal structure that plunges northward beneath the Holocene alluvium (Erickson, 2008). The deposits are composed of poorly sorted gravel, sand, silt, and clay interbedded with low permeability clays. The continental basin deposits have an approximate thickness of 1,500 feet in the southwestern part of the valley (Cardwell, 1965; Farrar, 1986). Based on post-depositional tilting in the southern portion of the valley, the deposits have been inferred to have a thickness up to 3,600 feet in the northern part of Little Lake Valley (Woolace, 2005).
Continental basin deposits generally have thick poorly sorted units with a low permeability and high porosity. Most wells in the continental basin deposits yield below 2 gpm and some drilled sites have yielded no water at all (Farrar, 1986). The Pliocene and Pleistocene continental basin deposits have been found to yield significantly less than Holocene alluvium, with yields ranging from less than 1 gpm to 45 gpm (Farrar, 1986). Few data are available for long term pumping test results, but yields may reduce over time from pressure reductions and low recharge rates, as water is pumped from the semi-confined to the confined aquifer. No estimates have been made for the groundwater storage capacity within the continental basin deposits due to their marginal capacity to yield water to wells (Farrar, 1986). Physical properties of Aquifer II including well yield, specific yield, specific capacity, and groundwater storage capacity, as identified by Farrar (1986), are summarized in Table 4-3 below.
Table 4-3. Physical Properties of Aquifer II Physical Property Value Well Yield <1- to 45- gpm. Specific Yield Not Specified Specific capacity 0.07- to 2.5- gpm/ft Groundwater storage capacity Not Specified
Aquifer II – Water Quality Similar to Aquifer I, the groundwater quality of Aquifer II in the continental basin deposits is characterized as bicarbonate type. Aquifer II contains approximately equal proportions of calcium, magnesium and sodium when compared to groundwater sampled from the deeper Holocene alluvium. However, the continental basin deposits have a higher proportion of sodium when compared to groundwater from shallower wells in the Holocene alluvium (Cardwell, 1965). Some wells within the continental basin deposits are characterized as sodium bicarbonate water, which is likely sourced from groundwater interacting with clay minerals in lake deposits (Cardwell, 1965).
4.1.3 Jurassic-Cretaceous Franciscan Complex The Franciscan Complex is not a principal aquifer, but a number of springs have developed along joints and fractures of this formation. Because well yields vary depending on the local rock type and degree of fracturing within the Franciscan Complex, the presence of groundwater is difficult to predict. However, well
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yields with adequate groundwater production for domestic use are generally limited to areas of highly fractured bedrock (Farrar, 1986).
Franciscan Complex - Physical Properties The depth of the Franciscan Complex varies across Little Lake Valley. Gravity models of Little Lake Valley indicate that the Franciscan Complex is deepest in the southern portion of the valley. As indicated by models, the fill thickness in the northern portion of the valley is approximately 820 feet thick, and fill thickness in the southern portion of the valley is approximately 3,280 feet thick. In addition, models show that although the valley fill has a regional 5 to 8 degrees north dip, the Franciscan basement floor slopes to the south (Erickson, 2008; Treasher, 1955; Cardwell, 1965; Woolace, 2005).
Well yields in the Franciscan Complex are difficult to predict since they vary by local rock type and degree of fracturing. Faulting occurs along the eastern side of the valley in the East Valley Fault zone, which is expressed by two faults, the westernmost of which is buried by valley fill. The East Valley fault no longer accommodates significant vertical slip and is mostly strike slip. The fault zone is Holocene active, but slip has not propagated to the ground surface (Erickson, 2008). While some drilled sites yield no water, some wells have yields up to 200 gpm. No estimates were made for the groundwater storage capacity within the Franciscan Complex due to its sporadic occurrence and marginal capacity to yield water to wells (Farrar, 1986).
Franciscan Complex - Water Quality Springs in the Franciscan Complex generally have high mineral content but acceptable chemical water quality has been encountered. Yields in wells that tap into Franciscan Complex bedrock have been reported to be impaired by high concentrations of chloride and boron. Because of the high mineral content of groundwater within the Franciscan Complex, water quality impacts in Aquifer I and Aquifer II as a result of recharge from the Franciscan Complex should be a consideration during water well development (DWR, 1958).
Groundwater extracted from wells in the Franciscan Complex have been reported to be approximately 6 to 8 degrees warmer than groundwater extracted from wells at a similar depth in the valley fill. This increase in temperature may result from a contribution to the groundwater from a deeper source (Cardwell, 1965). In addition to increases in temperature and mineral content in groundwater from the Franciscan Complex, gases emitted from wells have also been reported to be sourced from bedrock along the eastern side of the valley (Cardwell, 1965).
4.2 Historic Variations in Groundwater Levels Data from the 1950s indicate that groundwater levels in shallow wells in the Basin have considerable seasonal fluctuation in response to pumping and precipitation (North Coast Hydrologic Region, 2004). Farrar (1986) presented four hydrographs in Little Lake Valley with water-level records spanning 10 years or more prior to 1986. According to the hydrographs, groundwater levels fluctuate approximately 10 to 15 feet seasonally, and the seasonal fluctuation of groundwater levels between deeper water table wells is slightly greater. Water levels measured during the 1980s were nearly the same as water levels measured in the 1950s. One of the deepest wells showed a slight water level rise, but this was attributed to decreases in local pumping (Farrar, 1986; Cardwell, 1965).
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The Department of Water Resources (DWR) currently monitors five active and three inactive wells in the Little Lake Valley Groundwater Basin (DWR Water Data Library, 2020) through the California Statewide Groundwater Elevation Monitoring (CASGEM) program. Data date back to 1953 and monitoring of the wells is generally conducted during the spring and fall. Well information is presented in Table 4-4 below. The locations of these wells are shown on Figure 3-6.
Table. 4-4 DWR Groundwater Level Monitoring Wells State Well Total Depth Master Site Code Well Use Latitude Longitude Number (ft) 394104N1233159W001 18N13W17J001M 40 Residential 39.41064 -123.31695
394120N1233456W001 18N13W18L001M 91 Irrigation 39.41067 -123.34665
394164N1233489W001 18N13W18E001M 493 Unknown 39.41628 -123.3517
394243N1233270W001 18N13W08L001M 19 Residential 39.42452 -123.32704
394567N1233257W001 19N13W32L002M 44 Unknown 39.45596 -123.32938
394556N1233278W001 19N13W32L003M 120 Inactive 39.4556 -123.3278
394573N1233285W001 19N13W32F001M 138 Inactive 39.4573 -123.3285 394022N1233214W001 18N13W20H004M 26 Inactive 39.4022 -123.3214
No significant long-term trends in groundwater levels have been identified; trends have been observed to be relatively flat to slowly recovering from heavy well pumpage and drought (North Coast Hydrologic Region, 2004; Johnson, 2008). During the spring, first encountered groundwater fluctuates approximately between ground surface (0 feet bgs) and 5 feet bgs, and during the fall, groundwater fluctuates approximately 15 to 30 feet bgs. Declines in groundwater level were recorded between 1966 and 1978 in a well east of Willits. The declines were attributed to heavy pumping in the area followed by drought that occurred between 1975 and 1977. However, following the drought, groundwater levels quickly recovered (Johnson, 2008). Less significant declines can be observed during all recent drought years but following droughts, groundwater levels are observed to quickly recover. Historical, recorded groundwater level data from wells monitored by DWR in Little Lake Valley is presented in Chart 4-1. DWR Groundwater Level Monitoring by Year, with drought years identified highlighted in gray.
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Chart. 4-1 DWR Groundwater Level Monitoring by Year
4.3 Historic Groundwater Pumpage According to Farrar (1986), groundwater pumpage for all uses in Little Lake Valley historically averaged approximately 2,000 acre-feet per year. Farrar (1986) estimates that during the dry season, approximately 2,000 acre-feet contributes to the baseflow of streams. The groundwater quantity discharged to streams during the wet season has not been quantified; however, Farrar (1986) estimates that the groundwater reservoir refills most years.
4.4 Groundwater Recharge The main source of recharge in Little Lake Valley is precipitation (Johnson, 2008), with other sources of recharge including surface water infiltration, return flows from sewage and irrigation, and the potential upflow of groundwater in fault zones. Annual precipitation in the Little Lake Valley is approximately 51.9 inches (City of Willits, 2019). Precipitation directly infiltrates into the Holocene alluvium of Aquifer I, which is mostly unconfined with pervious surface materials. In addition, several losing streams Little Lake Valley recharge into the Aquifer I. Minor sources of recharge may result from return flows from sewage disposal facilities and excess irrigation water. The City of Willits manages a municipal sewage system from which
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treated wastewater is either used to irrigate pastureland for fodder or discharged to Outlet Creek. Although individual septic systems contribute to groundwater recharge, the amount is likely negligible since it is assumed that a significant part of the water is lost to evaporation in the shallow soil (Farrar, 1986).
The continental basin deposits make up a semi confined to confined aquifer. Recharge for Aquifer II occurs as precipitation flows over the surface of impermeable clay layers until it reaches permeable recharge areas, such as the contact zones between the Holocene alluvium and the continental basin deposits. Other permeable recharge areas include flow through confining beds or through fractures and faults. High concentrations of sodium, chloride and boron analyzed from water samples along the eastern portion of the valley supports that groundwater may infiltrate through faults (Farrar, 1986).
“Comparison of precipitation records for stations in Little Lake Valley (California Department of Water Resources, 1981) with spring water-level measurements indicates that levels recover to normal if precipitation is at least 75 percent of normal during the preceding rainfall season. The available data for Little Lake Valley are not sufficient to ascertain if lesser amounts of precipitation would return water levels to normal; however, data from Ukiah Valley indicate that precipitation in excess of 60 percent of normal during the preceding season is enough to fully recharge the ground-water reservoir.” (Farrar, 1986).
The Final Technical Report for Climate and Natural Resource Analyses and Planning prepared by the North Coast Resource Partnership (NCRP) in 2018 presents historical and projected recharge for groundwater basins to predict the end-century average recharge rate for a hot, low rainfall climate. Historical data between 1951 and 1981 indicate that Little Lake Valley had a recharge rate of 25.4 inches per year. Towards the end of the century the recharge rate is quantified to decrease 27 percent to an average recharge rate of 18.6 inches per year (NCRP, 2018).
5.0 SURFACE WATER HYDROLOGY This section provides a description of the surface water features within the Basin and immediate surrounding watersheds. A discussion of the reservoirs and lakes that supply water to the Basin and communities surrounding the Little Lake Valley, and are located in watersheds surrounding the Lower Davis Creek watershed, is additionally provided below.
It should be noted that the term “basin” can be used to describe both watershed basins and groundwater basins; however, these types of basins are separate and distinct. The basins and subbasins described in the following sections refer to the watershed basin, unless otherwise stated.
5.1 Surface Water Systems and Waterbodies The Basin (Little Lake Valley groundwater basin) is located within the Outlet Creek basin of the Upper Main Stem of the Eel River. The Outlet Creek basin is divided into three (3) subbasins: the Northern, the Middle and the Southern. The Basin is within the Southern subbasin of the Outlet Creek basin, which in turn is comprised of seven (7) watersheds. Of these seven (7) watersheds, the Basin is within the boundaries of the Lower Davis Creek watershed (CDFG, 2007). A visual depiction of the Outlet Creek basin, subbasins, and watersheds is provided on Figure 5-1. A summary of the hierarchy of the Lower Davis Creek watershed as it applies to the Basin is provided below.
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Table 5-1 Summary of Hierarchy of Lower Davis Creek Watershed Level Identifier
River Upper Main Stem of the Eel River Basin Outlet Creek
Subbasin Southern
Watershed Lower Davis Creek Groundwater Basin Little Lake Valley
The Lower Davis Creek watershed contains numerous streams, and a seasonal lake / wetland that will be discussed further in the following sections.
5.1.1 Streams The Basin, located within the Lower Davis Creek watershed, as mentioned above, contains numerous streams, all of which flow toward the north and converge into Outlet Creek. Stream flows within the Basin are generally high in the wet season (December through May) and low-to-dry during the dry season (June to November) (U.S. DOT, 2002). Streams are seasonally gaining streams that are fed by groundwater flowing within the Quaternary Alluvium of the Basin and precipitation. During the dry season, the streams may be losing when the depth to groundwater is below the stream bed and stream channel alluvium. This seasonal discharge and gauge height is recorded in United States Geological Survey (USGS) stream gauge (No. 11472180) located on Outlet Creek (USGS, 2020). Stream gauge locations within the Basin are shown on Figure 3-1.
5.1.2 Little Lake Little Lake, a seasonal lake that becomes a wetland during the dry season, is located at the northern extent of the Basin. The most highly saturated area of the Little Lake is shown generally on Figure 3-4. The water from the seasonal lake and wetland drains northwesterly through the Outlet Creek outlet from the basin (DWR, 2004). The seasonal feature of Little Lake and the wetland are due to high groundwater from the shallowing of the bedrock toward the north end of the Basin (Cardwell, 1965). During periods of extended rainfall, when groundwater levels are high, and when drainage discharge exceeds the capacity of the Basin outlet on Outlet Creek, water accumulates to form Little Lake. While flooding of the Basin has been partially corrected by artificial drainage that flows into Outlet Creek, major floods have occurred in 1955, 1964, and 1974. In the 1964 flood, Little Lake reached a surface area of approximately 2,200 acres and had a storage capacity of 22,000 acre-feet (U.S. DOT, 2002).
5.1.3 Surface Water Facilities While Little Lake is the only lake located within the Lower Davis Creek watershed Basin, several reservoirs and lakes that are used to provide water supply to the Basin and neighboring populations are located within watersheds adjacent to the Lower Davis Creek watershed, as shown on Figure 3-1 and Figure 5-1. A summary of the waterbodies and the streams they divert, if any, are provided below in Table 5-2.
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Table 5-2. Summary of Surface Water Facilities Facility Identification Diversion Source Watershed
Morris Reservoir Davis Creek Upper Davis Creek Centennial Reservoir Davis Creek Upper Davis Creek Willits Creek Twin Lakes None Willits Creek Lake Emily Willits Creek and Dutch Henry Creek Willits Creek and Dutch Henry Creek Willits Creek Lake Ada Rose tributaries Lake Wente Berry Creek tributaries Berry Creek Chinquapin Reservoir Moore Creek Upper Davis Creek
Of the waterbodies identified in Table 5-2, above, the Morris Reservoir and the Centennial Reservoir are managed by the City of Willits and are the only waterbodies used as potable water supply within the Basin as they are part of the City of Willits water distribution system. As previously discussed above and in Section 3.6.2., surface waterbodies in the watersheds surrounding the Basin are utilized to serve neighboring populations outside the Basin.
Water supply for potable and agricultural use is derived from the streams within the Outlet Creek southern subbasin, as shown on Figure 5-1. Points of diversion, locations where water is diverted from streams of the watershed, are located throughout the Basin and subbasin. These points of diversion are privately permitted, licensed, and registered to allow individuals to beneficially use reasonable amounts of water. A summary of points of diversions within the Basin and surrounding areas is provided by the Division of Water Rights in the electronic Water Rights Information Management System (SWRCB, 2020).
5.2 Surface Water Quality Within the Basin, streams may be seasonally gaining or losing; therefore, surface water and shallow unconfined groundwater systems are typically connected. Since the surface water and unconfined groundwater systems are connected, water quality degradation for one system has the potential to degrade water quality for the other. Water quality degradation to surface waters can be naturally occurring, from point sources, and from nonpoint sources. These three potential surface water quality degradation pathways are discussed further in the sections below.
5.2.1 Naturally Occurring Changes to water quality within surface water can occur from the surrounding geologic formation; however, presently there are not enough current publicly available surface water sampling data to define the natural occurring constituents in surface waters. The only publicly available surface water quality information on naturally occurring constituents is presented in the Geological Survey Water-Supply Paper 1548 in which surface water samples were collected from eight streams within the Basin circa the 1950s and analyzed for the constituents shown in Table 5-3, below (Cardwell 1965). Results from sampling indicated that stream waters are of bicarbonate type and contain the following constituents at the average levels, below.
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Table 5-3. Chemical Properties of Surface Water Samples Constituent or Characteristic Value Dissolved solids 64 to109 ppm;
Hardness (CaCO3) 31 to 77 ppm Chloride 2.5 to 4.2 ppm Percent sodium Average 25 percent Boron 0.01-0.19 ppm Iron 0.1 to 0.6 ppm
Surface water samples were collected from the head of the tributary creeks to Outlet Creek and from the outlet to the Basin. The water sample at the outlet of the Basin had higher total dissolved solids than the samples collected at the tributary heads. Cardwell identified that the reason for the change in total dissolved solids was due to the inflow of groundwater at the northern end of the Basin that has a higher concentration of total dissolved solids (Cardwell 1965).
5.2.2 Point Source Impacts Potential point sources within the Basin include leaking underground storage tanks, chlorinated solvent releases, landfills, industrial spills, private and municipal wastewater systems, and agriculture. Records for property locations that affect or have historically affected the groundwater and/or surface water quality within the Basin are provided on GeoTracker, an online public database provided by the State Water Resources Control Board (SWRCB).
Drought conditions can also lead to water quality issues in surface water systems, as happened in 2014 when low water levels in the Morris and Centennial Reservoirs led to rising water temperatures that led to elevated concentrations of organic compounds due to increased biological growth (LACO, 2019). Due to the higher concentrations of organic compounds, additional disinfection byproducts were created following disinfection of the surface water, resulting in citations from the SWRCB Division of Drinking Water for trihalomethane levels above maximum contaminant levels.
5.2.3 Non-Point Source Impacts Non-Point source impacts are natural and anthropogenic pollutants transported in stormwater runoff. These can include the oil, grease and other harmful constituents conveyed through urban runoff, and bacteria, nutrients, pesticides, herbicides, and fertilizers from agricultural land runoff. Additionally, these can include naturally occurring pollutants such as sediment from eroding streambanks.
While urban and agricultural runoff may impact surface water quality, at present, surface water quality is only listed as impaired for temperature and sediment by the State of California and the U.S. EPA, in accordance with Section 303(d) of the Clean Water Act (U.S. EPA, 2004). Increased stream temperatures may be attributed from removal of riparian vegetation, road building, grazing, urbanization, changes in the timing and amount of natural streamflow and increase in sediment. Likewise, increased sediment may be attributed by natural sources such as landslides and floods, or by removal of riparian vegetation, and road building.
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6.0 COMPONENTS OF THE GROUNDWATER MANAGEMENT PLAN
6.1 Goals and Objectives Through implementation of this GWMP, the City of Willits is establishing its groundwater management program for the portion of the Basin within city limits by elaborating upon current actions and regulations and proposing future actions. Based on review of the existing studies and water level data provided by DWR, it is apparent that there is a large volume of groundwater in the Little Lake basin and the groundwater levels recharge very quickly, even during and following multi-year drought events. These findings support the DWR designation of the basin as very low priority. This abundance of groundwater does not, however, relieve the City and other groundwater users from being responsible consumers of this natural resource and effectively managing the quantity of both groundwater and surface water available within and around the basin as well as protecting the quality of that water at the source.
6.1.1 Groundwater Management Goals The groundwater management goals for this GWMP seek to maintain and/or enhance groundwater and surface water quality and quantity, thereby providing a sustainable, high quality supply for agricultural, environmental, and urban uses into the future that remains protective of the health, welfare, and safety of all residents and water users. All future actions must be consistent with these goals and must contribute to achieving these goals. The groundwater management goals of the City of Willits are to:
1) Ensure a Reliable Water Supply for the City of Willits 2) Ensure Long-Term Groundwater Sustainability 3) Optimize Conjunctive Use of Surface Water and Groundwater 4) Protect Groundwater Quality 5) Facilitate Groundwater Replenishment and Cooperative Management Projects 6) Minimize the Effect of Groundwater Pumping on Surface Water Flows, Quality, Wetlands, and Natural Plant and Wildlife Communities
Each of these groundwater management goals will be best accomplished by: Developing a better understanding of the available groundwater and surface water resources, and the constraints and opportunities for efficient and effective management of these resources. Implementing and refining the BMOs over time. Executing coordinated and collaborative efforts among the City of Willits, water purveyors and water users in the general vicinity of the Basin.
6.1.2 Basin Management Objectives This GWMP intends to provide a framework for management of groundwater resources while sustaining the socioeconomic and environmental well-being of the community in and around the Little Lake Valley. Basin Management Objectives (BMOs) are a required component of groundwater management plans per Water Code § 10753.7 (a)(1) and are intended to set forth measurable objectives for the management of groundwater resources within the basin to maintain groundwater basin health. BMOs are flexible guidelines for the management of groundwater resources that describe specific actions to be taken by stakeholders to meet locally developed objectives for the groundwater basin. The BMO method of groundwater
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management is intended to provide a flexible approach that can be adapted to changing local conditions and increased understanding of the groundwater resource.
The BMOs proposed by the City of Willits are intended to address the management recommendations for the following: Groundwater Levels Groundwater Quality Surface Water and Wetlands
The BMOs presented herein are qualitative at this time and are intended to provide a basis for the City of Willits to determine, based upon data, appropriate hydrogeologic principles, and other relevant information, whether adverse impacts from groundwater pumping exist in specific cases. The City’s groundwater management processes are a critical component of implementing the BMOs. After data have been gathered, compiled and evaluated over a 3 to 4 year period and the Basin is better-understood, it may be appropriate to formulate quantitative BMOs.
The City recommends pursuing the development of a BMO program for the portion of the Basin within the City of Willits jurisdiction as part of the implementation of this GWMP. The City of Willits is a relatively new groundwater user and will expand the monitoring of the Basin as described herein in order to fully understand the Basin.
6.2 Groundwater Monitoring Groundwater monitoring is an important tool for the implementation of this GWMP. Ongoing monitoring of wells located throughout the Basin will provide information needed to document current conditions, assess long-term trends, and support further development of the components of this GWMP.
6.2.1 Monitoring of Groundwater Levels and Storage As discussed in Section 4.2, the Department of Water Resources (DWR) monitors five wells within Little Lake Valley on a semiannual basis. In addition, there are three inactive wells that have not been monitored since 2013. Monitored wells have hydrographs from historical groundwater data that date back to 1953. Wells are generally monitored in the spring (March) and fall (October). Monitored wells are mainly located in the central portion of the Little Lake Valley and they vary in depth. Two of the wells are located within the City of Willits, three wells are just east of the city limits, and three wells are located at the northern extent of Little Lake Valley. Figure 3-6 shows the location of the monitored wells (Caltrans, 2006; DWR, 2020). The Mendocino County Resource Conservation District provides monitoring services for wells in the Ukiah Valley under an agreement with the County of Mendocino and has been successful in expanding the monitoring well network in that area through the recruitment of new landowners. MCRCD is a potential partner for expanding the monitoring well network in the Little Lake Valley as well.
In addition to wells monitored by DWR, the City has three developed wells and numerous test and monitoring wells. The Elias Replacement well is approximately 200 feet deep and has an average flow of 170,000 gallons per day (gpd). The Elias Replacement well is currently used for additional drinking water supply and located north of the new groundwater treatment plant. In addition to the Elias Replacement well, the City owns and operates two additional developed wells (Long 20 Test well and the Park well) that are not currently used for drinking water supply. The Long 20 Test well is located southeast of the Elias Replacement well, is approximately 200 feet deep, and is screened in three depth zones. Currently, there is no pipeline between
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the Long 20 Test well and the groundwater treatment plant. The Park well is located south of Hearst Road and is approximately 240 feet deep (LACO, 2019).
6.2.2 Monitoring of Groundwater Quality Groundwater quality sampling and monitoring is conducted for public water systems and regulated by the California State Water Resources Control Board Division of Drinking Water. The City of Willits operates as a community water system in accordance with Water Supply Permit No. 02-03-08P2310004. The City owned and operated Elias Replacement well contributes to 5 to 10 percent of the total City of Willits water supply. Groundwater yielded from the Elias Replacement well has been reported to have high concentrations of iron and manganese, but arsenic is not present. It is treated by filtration and chlorination at the groundwater treatment plant prior to its release into the City of Willits water supply system (LACO, 2019).
The City analyzed groundwater quality samples for two developed wells not currently used to supply drinking water (the Park well and the Long 20 Test well), as well as numerous test and monitoring wells. Groundwater produced from the Park well has high concentrations of iron, manganese, and arsenic (LACO, 2014). Water sampled from the Long 20 Test well contained elevated levels of arsenic, iron, and manganese, but the arsenic level is much lower than that of the Park well. It was also impaired for odor. As previously stated, the concentration of arsenic increased with the depth of the well and the City may choose to isolate the upper two-thirds of the well to reduce treatment costs. Although the City has evaluated the Long 20 Test well as a drinking water supply there is currently no pipeline between the Long 20 Test well and the groundwater treatment plant.
It is likely that many private domestic users within the basin periodically test the water quality of their wells, but the State of California does not regulate domestic well water quality and therefore it is the responsibility of the owner to ensure that domestic well water is safe. Although private domestic well water quality is not regulated by the State, the State Water Resources Control Board (SWRCB) has implemented a Groundwater Ambient Monitoring and Assessment Program (GAMA). The GAMA program offers free chemical analysis to volunteer private well owners who participate in the study. Analytical results are used to evaluate the quality of groundwater used by private well owners. The program monitors: Bacteria indicators; General minerals and ions ; General chemistry parameters; Inorganics; and Organics.
Additional groundwater monitoring can be found on the Geotracker database, which serves as a reporting platform for data generated during investigation and remediation of known contaminated sites but does not provide a complete, basin-wide interpretation of groundwater quality issues. However, this resource can be used for documenting the concentrations, extent, and migration of groundwater contaminants related to known problem sites such as the old Remco Facility or the former Redwood Empire Cleaners location.
6.2.3 Inelastic Land Subsidence Monitoring
Subsidence occurs from the over pumping of aquifers. When large quantities of groundwater are withdrawn from aquifers, sediments within the aquifer compact and the ground level lowers. The magnitude of subsidence that can occur greatly depends on the composition of sediments within aquifer. As discussed in Section 4.1 above, the Holocene deposits in Aquifer I are composed of uncemented gravel, sand, silt, and
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clay, which makes them high in porosity and permeability. The Continental Basin deposits in Aquifer II have a high porosity but a low permeability since they are composed of poorly sorted gravel, sand, silt, and clay, with interbeds of clay that range in thickness from less than one foot to more than 100 feet. When over pumping occurs, a decrease in water pressure in sand and gravel causes a slow drainage of water from clay and silt beds. Clay and silt are compressible so as water is withdrawn the beds compact. Compaction of these beds cause the land surface to lower and is often permanent as these beds cannot usually be rehydrated under ambient conditions.
Lands subsidence monitoring is not currently being conducted in Little Lake Valley. However, groundwater monitoring data indicates that groundwater levels have not significantly lowered. It is, therefore, unlikely that groundwater extraction has caused significant land subsidence on a regional scale. However, if groundwater extraction increases, several methods are available to implement a land subsidence monitoring program. As discussed in Section 6.2.1, groundwater level monitoring is conducted in several wells in the Basin and these wells could be used to monitor land subsidence. While monitoring wells, staff could also inspect the wells for indicators of subsidence, which may include elevation changes between well casings and ground surface or cracks in the well pad or ground surface. For a more accurate measurement of land subsidence, a network of extensometers could be installed or a GPS survey could be conducted over a set schedule.
6.3 Groundwater Resource Protection
6.3.1 Control of Saline Intrusion Saline groundwater intrusion is not a prominent concern in the Basin. However, elevated salinities have been recorded below a poorly defined depth along the northern and northeastern portion of the valley, resulting in water quality that may be unacceptable for some uses (Farrar, 1986). The cause of high salinities in some wells along the northern and northeastern portion of the valley have been attributed to their proximity to the fault zone located at the eastern and northeastern portion of the valley. High sodium concentrations in groundwater samples have also been attributed to groundwater exchange between the continental basin deposits and the Holocene alluvial deposits. In the southern part of the valley, groundwater from the continental basin deposits discharges into the Holocene alluvium (Cardwell, 1965).
Farrar (1986) reports groundwater samples with sodium chloride concentrations as high as 510 mg/L, 770 mg/L and 1,064 mg/L. The two lower concentrations were from groundwater samples collected from a well at a depth of 128 feet below ground surface (bgs). The highest concentration was collected from a gas exploration hole between a depth of 930 and 986 feet bgs (Farrar, 1986). In addition, 20 groundwater samples that were analyzed had boron concentrations ranging between 20 and 127,000 μg/L. Only four of the groundwater samples exceeded 2,000 μg/L and were identified in the northern part of the valley. Boron concentrations exceeding 1,000 μg/L are not acceptable for agricultural uses and, therefore, it is advised to analyze for boron in groundwater from newly drilled wells that are to be used for crops (Farrar, 1986).
6.3.2 Wellhead Protection and Recharge Area Protection The City of Willits Public Works Department provides services for wastewater, including sewer maintenance and plant operations; and municipal water treatment, including water conveyance and water system maintenance. The Mendocino County Department of Environmental Health (MCDEH) acts as the Certified Unified Program Agency (CUPA) for Little Lake Valley (CERS, 2015). There are several regulatory programs
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administered by the MCDEH for land use and hazardous waste that protect public health and groundwater. These regulatory programs include the following: Land use permits for on-site septic systems and water wells are permitted through MCDEH. Installation and abandonment of monitoring wells and borings are permitted through MCDEH (MCDEH, 2020). For above ground storage tanks, the MCDEH is responsible for implementing the requirements of the California Aboveground Petroleum Storage Act (DTSC, 2020). To prevent accidental releases of substances that pose a threat to public health and the environment, the MCDEH is responsible for implementing the California Accidental Release Prevention Program (Cal OES, 2020). For facilities where hazardous waste materials are treated, stored, or disposed of the Resource Conservation Act’s hazardous waste permitting program ensures proper management of hazardous waste through requirements established by the California Environmental Protection Agency (EPA, 2020). Operation of USTs are managed through the California Regional Water Board’s Underground Storage Tank Program. Leak prevention is under direction of MCDEH and underground storage tanks are permitted through the MCDEH for installation, repair and construction, and removal. Cleanup of leaking tanks is under the direction of the NCRWQCB. For the enforcement of UST requirements, the SWRCB locally provides assistance and reimbursements of monitoring and cleanup costs through the Underground Storage Tank Cleanup Fund (USTCF). Tank integrity testing is required by law and must be performed by State-licensed tank tester and meet the requirements of the SWRCB (Waterboards, 2020).
6.3.3 Administration of Well Abandonment and Well Destruction Program Well construction and destruction standards are necessary for the protection of aquifers. Recommended statewide well standards for the protection of groundwater quality are contained in the Department of Water Resources Bulletin 74-81 and Bulletin 74-90. These bulletins contain minimum well standards for protecting groundwater quality; however, they are not always adequate for local conditions. In Mendocino County, water well and monitoring well permits are issued by the MCDEH, which requires that construction, repair, alteration, and destruction of wells follow the State of California (California Well Standards Bulletin 74-81 and 74-90), and the Mendocino County Well Ordinance (County Code Chapter 16.04). New wells are required to meet minimum construction standards and existing wells that are no longer in use are required to follow well destruction standards. Under the Mendocino Monitoring Well Application, known contaminated sites must also comply with standards of the North Coast Regional Water Quality Control Board (NCRWQCB), which require an approved workplan before any field work is initiated.
6.3.4 Well Construction Policies MCDEH administers the well permitting program in Mendocino County. Wells constructed within Mendocino County must comply with the Mendocino County Well Ordinance that was adopted on April 4, 1994 (Mendocino County, 1994) and regulations of the State California as they pertain to well construction. The Mendocino County Well Ordinance requires that the latest California Well Standards developed by the California Department of Water Resources be used (DWR, 1991). The MCDEH is the local enforcing agency responsible for issuing permits and enforcing standards that are equal to or more stringent the California Well Standards (DWR, 1991).
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6.3.5 Construction and Operation of Groundwater Projects Groundwater projects, as defined by the CWC Chapter 3 Section 10753.7 (d), include the construction and operation by the local agency of groundwater contamination cleanup, recharge, storage, conservation, water recycling, and extraction projects. New groundwater projects proposed within the area covered by this GWMP Basin that would directly affect groundwater levels or quality shall be constructed and operated in conformance with this GWMP and in collaboration with the applicable state and federal agencies. While the area covered by this GWMP is currently limited to the lands within the City of Willits jurisdiction, the sustainable management of the Basin would require collaboration and coordination with groundwater purveyors and users in the Basin as a whole.
6.3.6 Mitigation of Conditions of Overdraft As described above, the City of Willits is presently engaged in improving its groundwater system in order to increase its conjunctive use capabilities in order to facilitate groundwater use in the event the existing surface water supply becomes untenable. Presently, the principle source of potable water supply is surface water provided by the Morris and Centennial Reservoirs. Historically, these reservoirs have been depleted and subject to low water levels causing poor raw water quality during times of drought. Since most of the potable water supply is presently derived from surface water, the City is seeking to supplement the surface water supply with groundwater to provide a more robust drinking water supply for the City water users and be better prepared to address future challenges stemming from potential changes to the availability or quality of its surface water supplies. While overdraft has not been identified as a principal concern in the Basin, the City understands the importance of continuous monitoring of both sources of raw water to ensure that any impacts to either source are identified and mitigated.
6.3.7 Replenishment of Groundwater Extracted by Water Producers To preserve groundwater resources, groundwater recharge must be protected, enhanced, and/or supplemented. Preservation of groundwater resources can be protected by applying increased conservation and efficiency programs. Conservation and efficiency programs can lessen the demand on water withdrawal. Conservation and efficiency programs can be related to using water conserving fixtures and irrigation systems, shifting landscape irrigation to the evenings to reduce the rate of evapotranspiration, and education and public outreach.
Presently, the City of Willits conserves groundwater by recycling water that is treated at the wastewater treatment facility. Following treatment, the water is used to support enhancement wetlands, allowing a small amount of replenishment by percolation. In addition, the recycled water is supplied to local ranchers in the Basin to be used as irrigation water which helps reduce additional extraction from groundwater.
6.4 Groundwater Management Coordination As described in Bulletin 118 (DWR, 2003), water law in California treats groundwater and surface water as two separate and largely distinct water resources. This has historically led to managing these resources separately. However, in most cases and in the Little Lake Valley in particular, separate management is not sustainable nor recommended due to the interconnected nature of surface water and groundwater resources. The City of Willits, through implementation of this GWMP, seeks to coordinate management of the water resources in the Basin and surrounding areas with existing and future water resource managers and users.
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6.4.1 Facilitate Conjunctive Use Operations
Conjunctive use operations involve groundwater extraction from a groundwater basin, surface water storage, and a conveyance system. The City of Willits seeks to expand its conjunctive use capabilities in order to ensure a reliable water supply for water users in the City of Willits and surrounding areas. As described in Section 3.6.1, above, until recently, the City of Willits sourced its potable water supply solely from surface water reservoirs in the Lower Davis Creek watershed: the Morris Reservoir and the upstream Centennial Reservoir. Water from these sources is treated at the surface water treatment plant located near Morris Reservoir and is piped to the City of Willits and surrounding areas approximately 2.5 miles via a single transmission line.
In accordance with regulations of the California Department of Health Services, the City of Willits is required to demonstrate the adequacy of its water supply for projected demand and drought conditions. The Morris Reservoir’s capacity exceeds water demands and inflow stream requirements during most annual wet seasons. However, the reservoir’s storage does not always adequately meet demand during periods of drought (Johnson, 2008; LACO, 2019). The system’s dependence on a single surface source makes it vulnerable to catastrophic failures and to drought, as was demonstrated in 2014.
In late 2013, reservoir water volumes had dropped to critical levels due to drought. The City of Willits declared a “Stage 1 Water Shortage Emergency” August 14, 2013. On November 18, 2013, the City of Willits declared a “Stage 2 Water Emergency,” and called for voluntary conservation. The City of Willits staff also began working on plans to use city-owned wells, which were previously used exclusively as test wells and for irrigation water, as supplementary water sources. By January 2014, the City of Willits declared a “Stage 5 Water Emergency” and called for mandatory restrictions. The drought not only placed a strain on the quantity of water available but also led to reduced levels in the reservoirs which resulted in increased temperatures and biological growth, including algae blooms. Such organics overwhelmed the system, leading to water quality violations for total trihalomethanes (TTHM) over two periods in 2015. During that period, the City developed the Elias well system as an emergency project to supply and treat supplementary groundwater during periods of drought. The Elias well system included construction of a new groundwater treatment plant and the installation of over 8,000 feet of new water line to connect the Elias Replacement well to the distribution system. The groundwater treatment facility was installed due to the distance and difference in treatment required for the groundwater as compared to the surface water sources. The City additionally installed the Long 20 Test well in 2017; however, it is not connected to the Elias well system or the City’s drinking water facilities at this time.
In 2017, non-emergency use of this groundwater supply was approved by the State Water Resources Control Board (SWRCB) Division of Drinking Water, providing the City with the ability to supplement the surface water supply with groundwater and increase water supply reliability throughout the year. However, in the event that the surface water supply is compromised as it was in 2014, the City does not currently have the infrastructure necessary to fulfill the demand with groundwater.
In 2019, the City of Willits submitted an application to the North Coast Resource Partnership (NCRP) for Proposition 1 grant funding for a groundwater improvement project that includes additional improvements to the groundwater treatment and supply system to facilitate increased use of groundwater supplies to supplement existing surface water resources, when needed. The project, titled “Improving Willits Water Supply Reliability and Drought Resiliency with Groundwater and Conjunctive Use,” has the objective to increase the groundwater capacity to meet water supply demands of the City of Willits water supply system independent of surface water supply in the event the surface water supply becomes untenable due to extreme conditions
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such as the 2014 drought, or a compromised transmission line. Other benefits include providing the water system operators with the ability to manage the surface water treatment plant in conjunction with the groundwater treatment plant in order to control the water quality and reservoir levels, reducing treatment costs and reporting requirements (City of Willits, 2019).
During review of the grant funding application, some reviewers expressed concern regarding the statement in the Water Supply Planning Study (West Yost Study, West Yost, 2006) that “the principal downside of a groundwater supply [improvement] is its uncertain capacity to accommodate growth beyond 2025.” The uncertainty expressed in the West Yost study stems from a series of assumptions regarding population growth trends and groundwater aquifer characteristics based on existing data (and the lack thereof) at the time of the study. In the subsequent years, additional data has become available which can provide further insight into these parameters and provide a more complete understanding of the sustainability of newly-developed groundwater resources.
The West Yost study estimated the City of Willits population will reach 7,050 by the year 2025, utilizing a 1.66% annual growth rate sourced from California Department of Finance via the 2003-2008 City of Willits General Plan Housing Element. That growth rate has not been realized, with United States Census and American Community Survey Data estimating that the City of Willits contained 5,073 people in 2000 and 4,893 people in 2018, indicating an actual growth rate of -3.54% over that timeframe. Though population trends can vary over time, the City of Willits has consistently seen flat or negative growth rates since 2000, with the California Department of Finance most recently estimating a population growth rate of -0.9% from 2019 to 2020. In addition, the projected housing stock available has not grown at the rates anticipated in the West Yost study; in order to accommodate 7,050 residents at an average rate of 2.49 persons per household (the City of Willits average from 2010-2020, as estimated by the California Department of Finance), the City would require approximately 2,831 housing units. The California Department of Finance estimates that the City of Willits contained 2,028 housing units in 2006 and 2,109 units in 2020, representing an addition of 5.8 housing units annually. Given these trends, and assuming that efforts at the State level to accelerate housing production double the pace of housing production in the City of Willits over the coming years, it will take approximately 62 years before housing stock can accommodate the 2025 population estimate from the West Yost study.
Similarly, the West Yost Study, in examining the potential for groundwater resource development as a supplemental water supply, assumes that the maximum reliable pumping capacity of any proposed wells is 330 gpm per well. However, this assumption is not explained or supported elsewhere in the text. In July 2015, the City conducted an aquifer test during the construction and development of the Elias Replacement well. The findings in the report prepared by GHD states that the well can readily produce 400 gpm with production flow rate between 600 and 800 gpm being achievable (GHD, 2015). Then in September 2018, the City conducted an aquifer test during and following the installation of the Long 20 Test well (LACO, 2018). Based on this evaluation, the sustainable yield of the quaternary alluvium formation in which the Long 20 Test well is screened could be as high 3,700 gallons per minute, and, due to the size of the Long 20 Test well screening slots, the maximum recommended pumping rate is 560 gallons per minute. While more study and additional data are needed to better quantify the estimated total quantity of water available in the Little Lake Valley Basin and the estimated annual recharge rate, data from the Long 20 Test well indicates that the 330 gpm maximum reliable pumping capacity estimate in the West Yost Study could be too conservative and may not accurately represent basin conditions.
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6.4.2 Relationships with Local, State, and Federal Entities To effectively manage groundwater resources and facilitate implementation of this GWMP, coordination between local, state, and federal entities is necessary to achieve sustainable management of groundwater over the entire Basin, not just the portion underlying the City of Willits. Coordinating local and regional groundwater management is important to meeting the groundwater management goals of the City of Willits because groundwater, like other resources, does not respect administrative/jurisdictional boundaries, and actions outside the City of Willits can affect groundwater in the entire Basin and surrounding areas. The City of Willits will continue to foster and expand its relationship with the numerous entities listed below with oversight and/or interest in varying aspects of water resource management in the Little Lake Valley.
Local Entities The following local entities may have an interest in groundwater management as water users, landowners, local agencies with land use authority, and/or water resource managers. These entities may include, but are not limited to: Domestic water users Agricultural Landowners/Ranchers Sherwood Valley Band of Pomo Indians County of Mendocino Mendocino County Resource Conservation District (MCRCD) Existing and future water purveyors located within or in the area surrounding the Basin Environmental Advocacy groups such as the Willits Environmental Center
State Entities Existing state entities that have an interest in the use and availability of groundwater and surface water resources, and/or may directly impact water resources in the Basin through project implementation include: California Department of Water Resources (DWR) California State Water Resources Control Board (SWRCB) North Coast Regional Water Quality Control Board (NCRWQCB) California Department of Fish and Wildlife (CDFW) California Department of Transportation (Caltrans)
Federal Entities The following federal entities have interest in the interplay between water resources in the Little Lake Valley and the existing natural habitats: U.S. Environmental Protection Agency (EPA) U.S. Army Corps of Engineers (USACE)
6.4.3 Review and Coordination of Land Use Issues In order to ensure land use decisions are consistent with this GWMP, the following activities will occur: City of Willits Community Development Department staff will review proposed projects to ensure compliance with the goals of this GWMP. City of Willits Public Works Department staff will work cooperatively with water resource managers and users, and relevant local agencies in the area to increase the understanding of groundwater use and resources. City of Willits Community Development Department staff with the County of Mendocino and Brooktrails Township Community Services District (Brooktrails) to review proposed projects outside the
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City of Willits city limits. By keeping an open dialogue, the City of Willits will seek to stay informed of known groundwater conditions and activities underway or planned, which may affect the resources positively or negatively. With time and appropriate documentation of water management activities and monitoring, an understanding of the resources can be obtained so that groundwater conditions can be the result of deliberate water management choices.
7.0 GROUNDWATER MANAGEMENT PLAN IMPLEMENTATION AND FINANCING Implementation of the Little Lake Valley GWMP will require dedication of both time and financing from the City of Willits and the residents and property owners within the Little Lake Valley Groundwater Basin. The amount of time and financing required is dependent on the level of implementation of the Plan.
7.1 Plan Implementation This section addresses implementation of the Little Lake Valley Groundwater Management Plan and funding sources for each of the components of the Plan: Monitoring of Groundwater Levels and Storage: City and DWR monitoring programs are currently funded. An expansion of this monitoring effort would require additional funding allocations and coordination with stakeholders. Monitoring of Groundwater Quality: No specific action was recommended, therefore, there are no costs associated with the component. Should action be required in the future, supplemental funding may be required. Inelastic Land Subsidence Monitoring: No specific action was recommended, therefore, there are no costs associated with the component. Should action be required in the future, supplemental funding may be required. Control of Saline Intrusion: No specific action was recommended, therefore, there are no costs associated with the component. Should action be required in the future, supplemental funding may be required. Wellhead Protection and Recharge Area Protection: These activities are currently administered by City of Willits Public Works Department and the Mendocino County Division of Environmental Health under their current funding and authorities. The activities are supported by the Plan. Should additional activities be identified in a future GWMP update, supplemental funding may be required. Administration of Well Abandonment and Well Destruction Program: No specific action was recommended, therefore, there are no costs associated with the component. Should additional action be identified in a future GWMP update, supplemental funding may be required. Well Construction Policies: These activities are currently administered by Mendocino County Divisions of Environmental Health under their current funding and authorities. Should additional activities be identified in a future GWMP update, supplemental funding may be required. Construction and Operation of Groundwater Projects: New groundwater projects will require funding for design, construction and operation. Depending upon the entity proposing the project, funding may come from existing sources or new funding sources may be required. Mitigation of Conditions of Overdraft: Groundwater studies may necessary to determine the safe yield of the aquifer in areas outside of the City’s jurisdiction and in areas that the City has not already studied. The City will fund monitoring projects within its jurisdiction and potentially those areas within a reasonable vicinity of the City’s groundwater usage points and the respective radius of influence, Much of this type of data collection can be accomplished with existing funds, however, the
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additional groundwater studies will require substantial expenditures. Supplemental funding for the studies should be pursued. Replenishment of Groundwater Extracted by Water Producers: Protection of the recharge areas is currently regulated through Chapters 17, 21 and 24 of the County Code, Subdivision Regulation, Zoning, and Surface Mining and Reclamation, respectively. City staff will continue to work through these existing regulations to identify opportunities to protect the groundwater recharge areas. However, given the basin characteristics and the overlapping jurisdictions, it is not feasible for the recharge areas to be protected, if deemed necessary, without a multi-agency/stakeholder cooperative effort. No additional funding will be required to perform these functions at this time. Facilitating Conjunctive Use Operations: The City is currently expanding its conjunctive use operations using the City’s Water Enterprise Fund and funding through the NCRP Proposition 1 IRWM grant program. Development and construction of any future conjunctive use projects will require additional funding. Develop and Maintain Relationships with Local, State, and Federal Entities: The City of Willits maintains ongoing relationships with these entities under its current funding and municipal activities. Therefore, no additional funding is required. Review and Coordination of Land Use Issues: City of Willits staff will continue to coordinate project review with the County of Mendocino and Brooktrails to ensure projects proposed in the area protect the interests of the Little Lake Valley Groundwater Basin. No additional funding will be required to perform these functions.
7.2 Plan Financing Based on review of the City of Willits’ adopted budget for fiscal year 2019-2020, it is expected that the City’s existing general funding source has insufficient revenue to pursue a robust suite of projects within the City of Willits city limits to implement all recommendations provided in this Plan. Additional funding will be necessary to fully implement all the identified components of this GWMP. In recognition of the need to assess the impact of the additional financing, an appropriate revenue plan for implementation of the Plan, including preparation of studies, and design, construction and operation/ maintenance of groundwater projects is warranted. This report is intended to serve, in part, as a basis for further evaluation and creation of a new revenue plan for groundwater management in the Little Lake Valley.
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8.0 REFERENCES California Department of Fish and Game (CDFG). September 2007. Coastal Watershed Planning & Assessment Program, Outlet Creek Basin Assessment, Draft. Available at: http://well95490.org/index.php?option=com_content&view=article&id=88&Itemid=141&jsmallfib=1 &dir=JSROOT/presentations&download_file=JSROOT/presentations/01Outlet_pgs1-29.pdf.
California Department of Toxic Substance Control (DTSC). 2020. Imperial CUPA Aboveground Petroleum Storage Act Program. Accessed March 2020. Available at: https://dtsc.ca.gov/imperial-cupa- aboveground-petroleum-storage-act-program/.
California Department of Transportation (Caltrans). October 2006. Willits Bypass Final Environmental Impact Statement/Environmental Impact Report.
California Department of Water Resources (DWR). December 1981. Bulletin-74-81-Water-Well-Standards State of California. Accessed March 2020. Available at: https://www.acwd.org/DocumentCenter/View/169/Bulletin-74-81-Water-Well-Standards---State-of- California?bidId=.
California Department of Water Resources (DWR). Last updated February 27, 2004. California’s Groundwater Bulletin 118. North Coast Hydrologic Region – Little Lake Valley Groundwater Basin.
California Department of Water Resources (DWR). 1991. California Well Standards Bulletin 74-90. Available at: http://www.water.ca.gov/pubs/groundwater/water_well_standards__bulletin_74- 90_/ca_well_standards_bulletin74-90_1991.pdf.
California Department of Water Resources (DWR). 2020. Water Data Library. Available at: http://wdl.water.ca.gov/waterdatalibrary/.
California Department of Water Resources (DWR). 2019. Division of Integrated Regional Water Management (IRWM). 2019 Integrated Regional Water Management Grant Program Guidelines. Available at: https://water.ca.gov/-/media/DWR-Website/Web-Pages/Work-With-Us/Grants-And-Loans/IRWM- Grants/Files/P1-Guidelines/2019-IRWM-Grant-Program- Guidelines122319ay19.pdf?la=en&hash=731812CDA4515E09FA7A3A614D6F240DC9147260&hash=7 31812CDA4515E09FA7A3A614D6F240DC9147260.
California Department of Water Resources (DWR). August 5, 1987. Northern District. Groundwater Study, prepared in cooperation with the City of Willits.
California Department of Water Resources (DWR). December 1987. Northern District. Limnological Investigation of Morris Reservoir, report prepared in cooperation with the City of Willits.
California Environmental Protection Agency (CalEPA). 2015. California Environmental Reporting System (CERS). Unified Program Regulator Directory. Accessed March 2020. Available at: http://cersapps.calepa.ca.gov/public/directory/.
California Office of Emergency Services (Cal OES). 2020. California Accidental Release Prevention. Accessed
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March 2020. Available at: https://www.caloes.ca.gov/cal-oes-divisions/fire-rescue/hazardous- materials/california-accidental-release-prevention.
California State University, Chico, Center for Economic Development. 2018 Mendocino County Economic & Demographic Profile. Accessed March 2020. Available at: https://www.edfc.org/wp- content/uploads/2015/12/CED-2018-Mendocino-Economic-Demographic-Profile-compressed.pdf.
Cardwell. G.T. 1965. USGS Water Supply Paper 1548. Geology and Ground Water in Russian River Valley Areas and in Round, Laytonville, and Little Lake Valleys, Sonoma and Mendocino Counties, California.
City of Willits. August 28, 2019. Revised Agenda, Page 179. Item No. 10a. Accessed March 2020. Available at: http://www.cityofwillits.org/AgendaCenter/ViewFile/Agenda/_08282019-94
City of Willits. October 21, 2019. City of Willits General Plan. 2019 Safety Element - Public Review Draft. Accessed March 2020. Available at: https://cityofwillits.org/DocumentCenter/View/584/2019- General-Plan-Safety-Element-Update---Public-Review-Draft-.
City of Willits. August 12, 1992. General Plan Revision, Vision 2020. Accessed March 2020. Available at: https://cityofwillits.org/DocumentCenter/View/262/City-of-Willits-General-Plan?bidId=.
County of Mendocino. February 2012. Harris Quarry Use Permit and Reclamation Plan. Final Environmental Impact Report. Accessed March 2020. Available at: https://www.mendocinocounty.org/home/showdocument?id=28208.
Economic Development and Financing Corporation (EDFC). 2019. Community Profiles. Accessed March 2020. Available at: https://www.edfc.org/economic-development/community-profile/.
Erickson, Gwendolyn. May 2008. Evolution of an Intermontane Basin Along the Maacama Fault, Little Lake Valley, Northern California [Unpublished Master’s thesis]. Humboldt State University.
Farrar, C.D. July 1986. USGS Water-Resources Investigation Report 85-4258. Ground-Water Resources in Mendocino County, California.
Johnson, N.M. April 25, 2008. Water-supply reconnaissance (letter). Nicholas M. Johnson, PhD, RG, CHG, Water Resources Consultant.
LACO Associates. May 30, 2019. Technical Memorandum; NCRP: Disadvantaged Community Outreach & Technical Assistance for City of Willits Project. Improving Willits Water Supply Reliability and Drought Resiliency with Groundwater and Conjunctive Use.
Mendocino County. August 2009. Mendocino County General Plan. Accessed March 2020. Available at: https://www.mendocinocounty.org/government/planning-building-services/plans/mendocino- county-general-plan.
Mendocino County. 1994. Mendocino County Well Ordinance (County Code Chapter 16.04). Accessed March 2020. Available at:
Project No. 8509.07; Jul-2020 Page 36 of 38 Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
https://library.municode.com/ca/mendocino_county/codes/code_of_ordinances?nodeId=MECO CO_TIT16WASE.
Mendocino County. 1994. Mendocino County Well Ordinance and Special Permit Areas and Well Standards. Accessed March 2020. Available at: https://www.mendocinocounty.org/home/showdocument?id=2866.
Mendocino County. Not Dated. Department of Environmental Health (MCDEH). Land Use. Accessed March 2020. Available at: https://www.mendocinocounty.org/government/health-and-human-services- agency/envirnomental-health-eh/land-use
Mendocino County. Not Dated. Division of Environmental Health (MCDEH). Monitoring Well FAQ’s. Accessed March 2020. Available at: https://www.mendocinocounty.org/home/showdocument?id=9615.
North Coast Resource Partnership (NCRP). January 2018. Climate & Natural Resource Analyses and Planning for the North Coast Resource Partnership. A Technical Memorandum Summarizing Data Products. Final Technical Report. Accessed March 2020. Available at: https://northcoastresourcepartnership.org/site/assets/uploads/2018/06/NCRP_Report_Pepperwood _v3.pdf.
State Water Resources Control Board (SWRCB). 2020. eWRIMS – Electronic Water Rights Information Management System. Accessed May 2020. Available at: https://www.waterboards.ca.gov/waterrights/water_issues/programs/ewrims/.
State Water Resources Control Board (SWRCB). Page last updated March 25, 2020. Division of Water Quality. Underground Storage Tank Program. Accessed March 2020. Available at: https://www.waterboards.ca.gov/water_issues/programs/ust/
United States Census Bureau. Not Dated. Data Portal. Table: American Community Survey. Available at: https://data.census.gov/cedsci/all?q=willits%20city,%20California&g=1600000US0685600&tid=ACSD P5Y2018.DP05&layer=VT_2018_160_00_PY_D1&cid=DP05_0001E&vintage=2018.
United States Census Bureau. Not Dated. Quick Facts. Mendocino County, California. Available at: https://www.census.gov/quickfacts/mendocinocountycalifornia.
United State Environmental Protection Agency (EPA). May 4, 2020. Hazardous Waste Permitting. Accessed May 2020. Available at: https://www.epa.gov/hwpermitting.
United States Environmental Protection Agency (EPA). 2004. Upper Main Eel River and Tributaries (including Tomki Creek, Outlet Creek and Lake Pillsbury) Total Maximum Daily Loads for Temperature and Sediment. Accessed March 2020. Available at: https://www.waterboards.ca.gov/northcoast/water_issues/programs/tmdls/eel_river_upper_main/ pdf/uer-tmdl-final-12-28.pdf
United States Geological Survey (USGS). 2020. Outlet C NR Willits CA. Accessed April 9, 2020. Available at: https://waterdata.usgs.gov/monitoring-location/11472180/#parameterCode=00060&period=P1Y.
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West Yost & Associates. February 2006. Water Supply Planning Study, prepared for the City of Willits.
Woolace, Adam C. May 2005. Late Neogene and Quarternary Stratigraphy and Structure of Little Lake Valley, Northern Coast Range, California [Unpublished Master’s thesis]. Humboldt State University.
Project No. 8509.07; Jul-2020 Page 38 of 38 Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
FIGURES
Project No. 8509.07; July 13, 2020 LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG FIGURE PROJECT BY 1-1 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 6/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION WILLITS, CALIFORNIA DATE 8509.07 1-800-515-5054 www.lacoassociates.com PLAN AREA
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
NOTE: THE INFORMATION ILLUSTRATED IN THIS MAP WAS DERIVED FROM PUBLICLY AVAILABLE GIS DATA. LACO ASSOCIATES CANNOT GUARANTEE THE ACCURACY OF MENDOCINO THE DATA. COUNTY
PACIFI
C OCEAN PLAN AREA
05,000 Feet
LEGEND
WILLITS CITY LIMITS
Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri LITTLE LAKE VALLEY GROUNDWATER BASIN Japan, METI, Esri China (Hong Kong), Esri Korea, Esri (Thailand), NGCC, (c) OpenStreetMap contributors, and the GIS User Community FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN BY JRG 1-2 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 06/08/2020 8509.07 1-800-515-5054 www.lacoassociates.com LOCAL AGENCY BOUNDARIES
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
NOTE: THE INFORMATION ILLUSTRATED IN THIS MAP WAS DERIVED FROM PUBLICLY-AVAILABLE GIS DATA. LACO ASSOCIATES CANNOT GUARANTEE THE ACCURACY OF THE DATA.
BROOKTRAILS TOWNSHIP COMMUNTIY SERVICES DISTRICT
WENTE SCOUT RESERVATION
CITY OF WILLITS CITY LIMITS
PINE MOUNTAIN
MUTUAL WATER COMPANY
CITY OF WILLITS RESERVOIRS & SURFACE WATER 06,000 TREATMENT PLANT Feet
LEGEND RIDGE WATER SYSTEM
LOCAL AGENCY
SHERWOOD VALLEY RANCHERIA Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri LITTLE LAKE VALLEY GROUNDWATER BASIN Japan, METI, Esri China (Hong Kong), Esri Korea, Esri (Thailand), NGCC, (c) OpenStreetMap contributors, and the GIS User Community FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 3-1 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 111 E. COMMERCIAL STREET, WILLITS, CA DATE 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 8509.07 1-800-515-5054 www.lacoassociates.com SURFACE WATER MAP
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization. NOTE:THE INFORMATION ILLUSTRATED IN THIS MAP WAS DERIVED FROM PUBLICLY- D U T AVAILABLE GIS DATA. LACO ASSOCIATES C H CANNOT GUARANTEEEE CREE KTHE ACCURACY OF H TR NP E CK N THE DATA. RO R Y NP C R E EK E RE K R C W GE ILL DIG ITS CR EEK WIL D OA T CA NYO N C Lake Emily REEK B E E
B
REEK R A U CREEK Y N P P C
C TLET C H BERR R Twin U E C K CREEK O N EK R E O Lakes E E Y E R N K C A R C LE D G A I WQ17 B
D A Lake Ada Rose V
I S
C
R
E
WQ14 E WQ11 K WQ13 MILL WQ10 CREEK (AT WIL LIT WQ12 S)
WQ07 WQ09 Lake Winawa WQ08 WQ06 (Lake Wente) DUS CR AD EEK O R B
WQ05 A D Y WQ04 A FUL AR V W IBUT IET TR I ER C EK EK S RE CRE C TEL R CH E AE E B K
H K A E EH M E L WQ03 O ORE C R CR EEK WQ01 Chinquapin Reservoir EK CR E BAECHTEL
K EE R Morris C IS Reservoir V A D
Centennial Reservoir
M ARIPOSA CREE F K O R W S A Y L TH NP K E C E RE R EK D 0 6,000 C A R VI E S E C K R Feet EE K LEGEND R OC KY N P C USGS STREAM GAUGES LITTLE LAKE VALLEY GROUNDWATER BASIN R E E NP K STREAMS LAKES
N NP
P STATE HIGHWAYS NP Sources: Esri, USGS, NOAA FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 3-2 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 8509.07 1-800-515-5054 www.lacoassociates.com GEOLOGIC MAP OF LITTLE LAKE VALLEY
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
ERICKSON, 2008 FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 3-3 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 8509.07 1-800-515-5054 www.lacoassociates.com CROSS SECTION OF LITTLE LAKE VALLEY
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
FARRAR, 1986 FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN BY JRG 3-4 CLIENT CITY OF WILLITS CHECK RMD LACO JOB NO. EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 06/08/2020 8509.07 1-800-515-5054 www.lacoassociates.com LAND COVER MAP
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
LEGEND
LOCAL AGENCY BOUNDARIES
LITTLE LAKE VALLEY GROUNDWATER BASIN
LAND COVER
UNCLASSIFIED
OPEN WATER
PERENNIAL SNOW/ICE
DEVELOPED, OPEN SPACE
DEVELOPED, LOW INTENSITY
DEVELOPED, MEDIUM INTENSITY
DEVELOPED, HIGH INTENSITY
BARREN LAND
DECIDUOUS FOREST
EVERGREEN FOREST
MIXED FOREST
SHRUB/SCRUB
HERBACEUOUS
HAY/PASTURE
CULTIVATED CROPS
WOODY WETLANDS
EMERGENT HERBACEUOUS WETLANDS
NOTE: THE INFORMATION ILLUSTRATED IN THIS MAP WAS DERIVED FROM PUBLICLY-AVAILABLE GIS DATA. THE 2011 LAND COVER DATASET WAS DERIVED FROM THE NATIONAL GEOSPATIAL CENTER OF EXCELLENCE/ NATURAL RESOURCES CONSERVATION SERVICE OF THE UNITED STATES DEPARTMENT OF AGRICULTURE. LACO ASSOCIATES CANNOT GUARANTEE THE ACCURACY OF THE DATA.
0 4,500
Feet USGS The National Map: National Hydrography Dataset. Data refreshed March, 2020., Sources: Esri, USGS, NOAA FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 3-5 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 8509.07 1-800-515-5054 www.lacoassociates.com UNINCORPORATED AREA LAND USE MAP
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
MENDOCINO COUNTY GENERAL PLAN, 2009 FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN BY JRG 3- CLIENT CITY OF WILLITS CHECK RMD LACO JOB NO. EUREKA ● UKIAH ● SANTA ROSA LOCATION111 E. COMMERCIAL STREET, WILLITS, CA DATE 06/08/2020 8509.07 1-800-515-5054 www.lacoassociates.com EXISTING WELLS AND WATER LINE SERVICE AREA
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
LEGEND
WILLITS GROUNDWATER SYSTEM
DWR WELLS IN DATABASE
CITY OF WILLITS
LITTLE LAKE VALLEY GROUNDWATER BASIN
DWR GROUNDWATER LEVEL MONITORING WELLS
ACTIVE
ELIAS INACTIVE REPLACEMENT WELL LONG 20 WELL
GROUNDWATER TREATMENT PLANT
0 4,000 Feet
NOTE: 1. THE INFORMATION ILLUSTRATED IN THIS MAP WAS DERIVED FROM PUBLICLY-AVAILABLE GIS DATA.LACO ASSOCIATES CANNOT GUARANTEE THE ACCURACY OF THE DATA. FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 4-1 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 8509.07 1-800-515-5054 www.lacoassociates.com FEMA FLOOD ZONE MAP
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
D U T C H H E N REEK R EE C Y R KT C C R RO E E K K EE CR E R DIGG
ILD O W AT C A N YO W N C IL R L EEK IT S C B R E
CREEK E E E K B R REEK A
U C N
OUTLET C P Y P H C R C
EE BERR R K E K E E K E H
R A E C H R D LE L D / A A B A V I EC S HT C EL R C E R E E K E K
MI CREEK (AT LL WILLI TS)
BROADD US CREEK
K E E R
A C Y AR L UT H F B E ULW RI D IETE T A R EEK A C CR H R TEL V EE CH I K BAE S C R E EK
0 4,500
M O Feet O R E C K RE E
LEGEND EK BAECHTEL CR E LAKES / RESERVOIRS STREAMS LITTLE LAKE VALLEY GROUNDWATER BASIN FEMA FLOOD ZONE WITHOUT BASE FLOOD ELEVATION, ZONE A DAVIS CREEK WITHOUT BASE FLOOD ELEVATION, ZONE AE
FO REGULATORY FLOODWAY, ZONE AE R S Y Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, 0.2% ANNUAL CHANCE FLOOD HAZARD, TZONEH X E C REEK USDA, USGS, AeroGRID, IGN, and the GIS User Community FIGURE PROJECT LITTLE LAKE VALLEY GROUNDWATER MANAGEMENT PLAN JRG BY 5-1 RMD CLIENT CITY OF WILLITS CHECK LACO JOB NO. 06/08/2020 EUREKA ● UKIAH ● SANTA ROSA LOCATION 111 E. COMMERCIAL STREET, WILLITS, CA DATE 8509.07 1-800-515-5054 www.lacoassociates.com OUTLET CREEK WATERSHEDS AND SUBBASINS MAP
REUSE OF DOCUMENTS: This document and the ideas and design incorporated herein, as an instrument of professional service, is the property of LACO Associates and shall not be reused in whole or part for any other project without LACO Associates express written authorization.
Julelaine Creek Long Valley Creek Alder Creek
Bloody Run Upper Outlet Creek Creek Dutch Henry Creek
Lower Outlet Sherwood Creek Creek
Ryan Creek String Creek*
LEGEND Willits Creek STATE HIGHWAYS Berry Creek STREAMS
LITTLE LAKE VALLEY GROUNDWATER BASIN Lower Davis Creek LAKES / RESERVOIRS Willits Broaddus Creek CALWATER PLANNING WATERSHEDS
SUBBASIN
MIDDLE Baechtel Creek
NORTHERN Upper Davis Creek SOUTHERN
Note: Watershed data was derived from the CA Department of Fish and Game Coastal Watershed Planning and Assessment Program K. Pettit 9/2006; 02.5 Data Sources: DFG, CDF, USGS. LACO Associates Miles cannot guarantee the accuracy of the data. Sources: Esri, USGS, NOAA Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
APPENDIX A
Resolution of Intention
Project No. 8509.07; July 13, 2020
Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
APPENDIX B
GWMP Required, Voluntary, & Recommended Components
Project No. 8509.07; July 13, 2020
Little Lake Valley GWMP Components GWMP Section
Required Components (Section 10753.4 and 10753.7 of the Water Code) The local agency shall make available to the public and the department a written statement describing the manner in which interested parties may participate in 2.0 developing the groundwater management plan. Establish Basin Management Objectives (BMOs) for the Little Lake Valley groundwater 6.1.2 basin Include components relating to the monitoring and management of groundwater levels, groundwater quality degradation, inelastic land subsidence, changes in surface flow and surface water quality that directly affect groundwater levels or 6.2 quality or are caused by groundwater pumping in the basin, and a description of how recharge areas identified in the plan substantially contribute to the replenishment of the groundwater basin Prepare a plan to involve other agencies that enables the City to work cooperatively with other public entities whose service area or boundary overlies the groundwater 2.0 basin Prepare a map that details the area of the groundwater basin, the area that will be 1.2 subject to the plan, and the boundaries of other local agencies that overlie the basin Prepare a map that identifies the current recharge areas that substantially contribute TBD to the replenishment of the groundwater basin. Adopt monitoring protocols that are design to detect changes in groundwater levels, groundwater quality, inelastic land subsidence, and flow and quality of surface water 6.2 that directly affect groundwater levels or quality or are caused by groundwater pumping in the basin Voluntary Components (Section 10753.8 of the Water Code)
Control of saline water intrusion 6.3.1
Identification and management of wellhead protection areas and recharge areas 6.3.2
Regulation of the migration of contaminated groundwater 6.3.6
The administration of a well abandonment and well destruction program 6.3.3
Mitigation of conditions of overdraft 6.3.7
Replenishment of groundwater extracted by water producers 6.3.8
Monitoring of groundwater levels and storage 6.2.1
Facilitating conjunctive use operations 6.4.1
Identification of well construction policies 6.3.4 The construction and operation by the local agency of groundwater contamination 6.3.5 cleanup, recharge, storage, conservation, water recycling, and extraction projects The development of relationships with state and federal regulatory agencies 6.4.2 Review of land use plans and coordination with land use planning agencies to assess 6.4.3 activities which create a reasonable risk of groundwater contamination Recommended Components (Bulletin 118-2003) Document public involvement and ability of the public to participate in development 2.0 of the GWMP, this may include a Technical Advisory Committee (TAC)
Establish an advisory committee of stakeholders within the plan area that will help guide the development and implementation of the plan and provide a forum for the N/A resolution of controversial issues Describe the area to be managed under the GWMP including The physical structure of the aquifer system A summary of available historical data and issues of concern related to groundwater levels, groundwater quality, inelastic land subsidence, and surface water flow or quality that effects 3.0 groundwater or groundwater pumping that affects surface water flow or quality A general discussion of historical and projected water demands and supplies
Establish management objectives (MOs) for the groundwater basin 6.1.2
Create a Link between Management Objectives and Goals and Actions of the Plan 6.1
Describe the GWMP’s monitoring program 6.2.1 Describe efforts to coordinate with land use, zoning, or water management planning 6.4.3 agencies or activities Create a summary of monitoring locations with frequency of wells monitored 4.2 Provide periodic reports summarizing groundwater conditions and management activities including: A summary of monitoring results, with a discussion of historical trends A summary of management actions during the period covered by the report A discussion of whether actions are achieving progress towards TBD meeting the MOs A summary of proposed management actions for the future A summary of any GWMP changes that occurred during the period covered by the report A summary of actions taken to coordinate with other water and land agencies and other government agencies
Provide for the periodic re-evaluation of the entire plan by the managing entity TBD
Little Lake Valley Groundwater Management Plan – PUBLIC REVIEW DRAFT Prepared for City of Willits July 9, 2020
APPENDIX C
Public Outreach Documentation
Project No. 8509.07; July 13, 2020 PUBLIC OUTREACH PLAN
Little Lake Valley Groundwater Management Plan Development Prepared for the City of Willits
Date: January 2020 Project No.: 8509.07
Prepared By: Rebecca Dalske Associate Planner
Reviewed By: Rodney Wilburn, PE Vice President of Engineering
1.0 INTRODUCTION This technical memorandum describes the Public Outreach Plan for the development of the Little Lake Valley Groundwater Management Plan (GWMP). The City of Willits (City) seeks to develop the GWMP in order to receive Department of Water Resources (DWR) grant funds for a well improvement project. The GWMP will be developed through an inclusive process that will inform, consult, involve, collaborate with, and empower local stakeholders through public participation. Development, and ultimately implementation, of the GWMP will benefit from the active participation of those who have local knowledge and a stake in the outcome of the planning process. By focusing on engaging the public throughout the process, the GWMP will be a locally driven plan and will provide the stakeholders in the Little Lake Valley with an appropriate and implementable plan that will provide a basis for groundwater management for years to come.
1.1 Project Description
The City of Willits Department of Public Works (Public Works) is the City lead for groundwater-related activities within the City limits. The Little Lake Valley Groundwater Basin is a “Very Low” Priority basin as defined by DWR and is thereby not subject to the requirements of the Sustainable Groundwater Management Act (SGMA). In accordance with the Integrated Regional Water Management (IRWM) Grant Program Guidelines, the City is required to complete a GWMP within one year of the grant application submittal date in order to receive the grant funds. As of the drafting of this plan, the City Council has directed Public Works to develop a GWMP for the Little Lake Valley Groundwater Basin and has entered into a contract with LACO Associates (LACO) to lead the planning efforts and overall development of the GWMP. The GWMP is being developed under the authority provided in in the California Water Code, Division 6, Part 2.75, Chapters 1-5, Sections 10750 through 10755.4.
This Public Outreach Plan will support and inform the development of other components of the GWMP and guide the inclusion of local stakeholders in the process. Local stakeholders will help to define current and
Project No. 8509.07; January 2020 Page 1 anticipated groundwater management issues and opportunities, goals and objectives, the GWMP area and associated Basin Management Objective (BMO) areas, and GWMP implementation activities.
1.2 Public Outreach Objectives The City of Willits has identified the following objectives for public outreach: • Inform the public regarding the process for – and progress of – GWMP development; • Consult with interested stakeholders and the general public throughout the GWMP development process; • Involve stakeholders in determining the planning goals and objectives; • Collaborate with stakeholders to include their recommendations and concerns, where feasible; and • Empower the Little Lake Valley Groundwater Basin to develop a sustainable and manageable GWMP for the future.
To pursue these objectives, the City of Willits recognizes the need to match appropriate involvement opportunities and outreach methods with groups targeted for inclusion in the planning process. Some participants may merely wish to remain informed regarding the planning process, while others may be interested in participating directly in GWMP development. The public outreach process proposed in this Public Outreach Plan provides ample opportunity for both direct engagement and participation as well as passive tracking of Plan development progress.
2.0 OUTREACH IMPLEMENTATION LACO, under the direction of the City, will conduct outreach with a variety of public and private entities in the Little Lake Valley with an interest in the planning process and its results. Outreach to and coordination with departments and individuals within the DWR and the City will also be necessary. The entities targeted by this Outreach Plan are expected to have a range of potential outreach needs. The three categories below present the range of information needs that this Outreach Plan will seek to address. • Notification Group – This group merely needs to know that GWMP development is proceeding. Parties in this group may need to see formal progress reports, be notified that deliverables have been made, and should be notified when the GWMP is complete. • Information Group – This group may want to or need to learn about GWMP goals and approach and should be informed regarding the general progress of the GWMP development. • Input Group/Participatory Group – This group may wish to provide suggestions regarding GWMP development and should be given opportunities to learn about - and provide comments on - planning elements, methods, and documents. This group also may contain individuals with specific knowledge or experience related to the development of GWMP elements and should participate in decisions regarding development of Plan content.
The categories at higher levels of involvement are inclusive of those at more minimal levels of involvement. Those in the input group, for example, would have access to public information received by the notification and information groups.
2.1 Key Stakeholders Table 1 lists key groups that this Outreach Plan will target, at a minimum. The table describes each group’s assumed mission and/or interest in the plan and identifies the group’s assumed outreach needs, using the categories described above. It is likely that this stakeholder list will expand throughout the GWMP development process. In addition, levels of outreach and participation may vary both within each group
Project No. 8509.07; January 2020 Page 2 and over the course of plan development. In Table 1 groups anticipated to have ongoing decision-making involvement with the planning effort are presented first.
Table 1. Key Stakeholder Outreach Needs Outreach Stakeholder Interest in GWMP Needs Notes Some departments (Department of Public Works and City Council) will require notification and formal progress reporting. Representatives of other departments may want or need to be informed, provide input, and/or participate. Staff dedicated to the GWMP planning effort Leading the GWMP Participation City of Willits will participate. The Department of Public Works and City development / Input Council may take action only on formal tasks. Other departments should be informed regarding GWMP goals and should be provided with an internal contact to which they may direct their own (and external) inquiries regarding the GWMP. Direct knowledge and Water experience related to Development of several GWMP elements will focus on Participation Management water use in the Little groundwater sustainability and will require involvement / Input Districts Lake Valley and from individuals that utilize groundwater. surrounding areas. The Sherwood Valley Band of Pomo Indians has occupied the Little Lake Valley for generations and tribal members Tribe maintains may have insights into historical groundwater Sherwood sovereignty over lands Participation characteristics. The Tribe currently uses groundwater to Valley Band of overlying the Little Lake / Input supply a 15-unit housing development in the Little Lake Pomo Indians Valley Basin Valley, and the Tribe has expressed interest in developing further groundwater resources to support expanded Tribal housing development. Owners and operators of groundwater wells in the Development of several GWMP elements will focus on Little Lake Valley have Participation Well Owners groundwater sustainability and will require involvement direct knowledge and / Input from individuals that utilize groundwater. experience with groundwater. Various interests include protection and enhancement of: Interest by environmental advocacy groups typically Environmental habitat; wildlife focuses on groundwater / surface water interaction and Advocacy populations; and water, Information habitat where groundwater is a primary source of water Groups air, and terrestrial supply. resource quality. Many have education and outreach objectives. County of Information/ The County of Mendocino maintains jurisdiction over all Varies Mendocino Notification non-Tribal, unincorporated areas of the Little Lake Valley. The general public, especially those served by City of General Information/ Varies Willits drinking water infrastructure, may have input to Public Notification provide regarding the Plan and its components.
Project No. 8509.07; January 2020 Page 3 2.2 Planned Outreach Methods Just as public participants in GWMP development have a range of outreach needs, so too is there a range of methods for meeting those needs. The planning team can: make information available to the public; share information in a unidirectional manner; ask for public response; and can interact with public representatives in group settings. The range of outreach methods extends from “one-way” outreach methods to highly interactive decision-making.
Settings that provide interaction with interested parties and groups allow for both one-way and two-way communication, enhanced by discussion. These methods provide opportunities for extensive involvement through focused education and participatory decision-making. A public workshop, featuring informational presentations and discussion, is an example of an interactive method.
A variety of potential methods are appropriate for GWMP development, and a combination of the methods will help to provide the right information to the right people at the right time. This Outreach Plan identifies methods that may be utilized during Plan development; in order for the Outreach Plan to be effective, however, it must be adaptable based upon needs identified during the planning process. Monitoring the effectiveness of the outreach methods will provide the planning team guidance in evaluating and adjusting Outreach Plan implementation to meet the City’s objectives. Table 2 describes the outreach methods that may be employed during GWMP development and indicates a potential monitoring method for each.
Table 2. Potential Outreach Methods Method Description Provide written information to local newspapers for publication; take out ads Press Releases announcing events; or post public notices of upcoming events in the “calendar” section of local publications. A list of individuals and organizations with interest in the GWMP will be Email List maintained, and those individuals and organizations receive updates on the GWMP progress. Web Page - A dedicated section of the Public Works webpage will provide a Website means to disseminate Plan information via the Internet. Prepare and conduct two public workshops. The workshops will be open to and be primarily led by the public. Include opportunities for the public to ask Public Workshops questions of the planning team and to offer suggestions, either at the meeting or thereafter. Prepare and conduct two public hearings: one to adopt the resolution of intention to draft the GWMP; and one to adopt the final GWMP. Hearings will Public Hearings be open to the public and will provide information on the planning goals and approach.
2.3 Outreach Tasks Following completion of the Outreach Plan, LACO, with the support of the City, will implement activities described in the Outreach Plan. Outreach efforts will focus on public notification and interaction with public entities whose service area overlay groundwater basins. Outreach activities will include: • Ongoing public communications with interested stakeholders. • Public workshops: Two public workshops will be held during development of the GWMP. o Public Workshop 1: will provide the public with an overview of the GWMP development process and encourage public input on the issues and opportunities the GWMP should explore. The workshop will enable members of the public and relevant entities to join the email list described above and joining the planning effort to the extent feasible.
Project No. 8509.07; January 2020 Page 4 o Public Workshop 2: will allow the public to review and discuss the first draft of the GWMP. Public comment on the draft will be encouraged and will be considered for incorporation in the final draft of the GWMP, as appropriate. • Formal Public Hearings: Two public hearings will be held during the development of the GWMP, as required by the California Water Code (CWC 10753.2-10753.6) . th o Public Hearing 1: was held on December 11 during the Willits City Council meeting held on the same date. At this hearing, the City Council provided an opportunity for public comment, heard a brief presentation regarding the GWMP from LACO Associates, and adopted a Resolution of intention to develop a GWMP. o Public Hearing 2: will be held at a date to be determined, currently scheduled for August 2020. At this hearing, the City Council will again accept public comment on the Draft GWMP, hear a brief presentation on the Plan, consider any protests filed, and choose to either adopt or reject the Plan. The full noticing and hearing process for the Public Hearings is excerpted below: o Step 1 - Provide public notification of a hearing on whether or not to adopt a resolution of intention to draft a GWMP and subsequently complete a hearing on whether or not to adopt a resolution of intention to draft a GWMP. Following the hearing, draft a resolution of intention to draft a GWMP. o Step 2 - Adopt a resolution of intention to draft a GWMP and publish the resolution of intention in accordance with public notification (6066 gov. code). Upon written request, provide a copy of resolution of intention to interested persons. o Step 3 - Prepare draft GWMP within two years of resolution of intention adoption. Provide to the public a written statement describing the manner in which interested parties may participate in developing the GWMP. o Step 4 - Provide public notification (6066 gov code) of a hearing on whether or not to adopt the GWMP, followed by a hearing on whether or not to adopt the GWMP. o Step 5 - If protests are received for less than 50 percent of the assessed value of property in the county area the plan may be adopted within 35 days after completion of Step 4 above. If protests are received for greater than 50 percent of the assessed value of the property in the county area, the plan will not be adopted.
2.4 Outreach Schedule The following outreach schedule will be adjusted as needed during the Plan development process.
Table 3. Outreach Schedule Task Date Public Hearing to Adopt December 11, 2019 Resolution of Intention Stakeholder Outreach December 2019 – August 2020 February 20, 2020 Public Workshop #1 5:30pm-7:30pm DRAFT GWMP Released to Late April 2020 Public Public Workshop #2 May 2020 – Date TBD Public Hearing to Adopt August 2020 – Date TBD GWMP
Project No. 8509.07; January 2020 Page 5
Little Lake Valley Groundwater Management Plan Public Opinion Survey
The Willits City Council has approved the development of a Groundwater Management Plan (GWMP) for the Little Lake Valley Groundwater Basin in order to secure previously-approved half million-dollar Proposition 1 grant funding that the City will receive from California Department of Water Resources to continue constructing a new groundwater project that will bolster the City's water supply reliability. Stakeholder participation is essential to help to define current and anticipated groundwater management opportunities, goals, issues, and objectives.
This Public Opinion Survey is being provided to you, in the interest of soliciting input on current and historic observations of groundwater use in the Little Lake Valley. Hard copies of this Survey are available at one (1) of the two (2) public workshops to be hosted by the City of Willits, or online on the City of Willits website: http://www.cityofwillits.org/146/Water.
If completing a hard copy, please send your completed survey to:
Andrea Trincado 380 E. Commercial St. Willits, CA 95490
Please provide any of the following information that you would like to have included with your responses. All of this information is optional; however, information on well locations is appreciated.
Name: Email Address: Add to the GWMP email list? Address: APN: Organization:
General Water Use – Please circle all that apply:
1. What is your water source?
a. My land is in a water district
b. My land is outside a water district
c. I only use surface water
d. I only use groundwater (well or spring)
e. I use both surface water and groundwater (well or spring)
2. What do you use groundwater for?
a. Residential uses/Drinking water
b. Ranch land irrigation
c. Agricultural irrigation
d. Municipal
3. Have you had any problems with groundwater and/or your well?
a. I have not had any problems
b. Well or equipment failure
c. Low groundwater levels (pump sucks air)
d. High groundwater levels (ground saturation)
e. Poor water quality
f. Sand or sediment in the well/water
g. Other:
Please explain:
Water Quantity – Please answer all relevant questions and include general location information if able.
1. Have you seen any unexplained changes in your well or spring production in the past?
a. Yes b. No
2. If you answered yes to the question above, please answer the following questions and include as much information as you are comfortable providing.
a. Were the changes permanent?
b. How long did they last?
c. How long ago did they occur?
3. Have you heard of others having water supply issues with their well or spring?
Water Quality – Please answer all relevant questions
1. Do you test your groundwater quality regularly?
a. Regularly
b. Occasionally
c. Never
d. Other:
2. Do you have to treat your groundwater prior to using it?
a. Yes
b. No
If yes, please explain:
What are your main concerns regarding groundwater in the Little Lake Valley?
Little Lake Valley Groundwater Management Plan Stakeholder Meeting
February 13, 2020 @ 10:00am - 12:00pm City Hall – City Council Chambers 111 E. Commercial St., Willits
AGENDA
1. Opening Remarks and Introductions
2. Presentation on the Groundwater Management Plan (GWMP) Development Process
a. Meeting Purpose
b. Background
c. Public Participation Methods
d. Public Outreach Objectives
e. Plan Development Schedule
f. Area Affected by GWMP
g. Required Components
h. Example Groundwater Management Goals
i. Voluntary Components
3. Comments/Discussion
Please contact us at: [email protected] with any questions/comments/information. 5/1/2020
LITTLE LAKE VALLEY GROUNDWATER Meeting Purpose MANAGEMENT PLAN • Provide overview of the Groundwater Management Plan (GWMP). • Receive input and thoughts on groundwater management in the Little Stakeholder Meeting Lake Valley. February 13, 2020
Presented by LACO Associates on behalf of the City of Willits Rodney Wilburn, PE Rebecca Dalske
Background Public Participation Methods*
• City of Willits awarded ~$500,000 in Proposition 1 grant funding • Press Releases; through DWR in Fall 2019. • Email List; • As a condition of the funding, GWMP must be adopted by September • Website; 6, 2020 to be eligible for funds for well improvement project. • Public Workshops; and • City Council contracted with LACO Associates to prepare the GWMP. • Public Hearings. • City Council approved a Resolution of Intention to Draft the GWMP on December 11, 2019. *See Public Outreach Plan for further details on outreach methods
Public Outreach Objectives Plan Development Schedule
• Inform the public regarding the process for –and progress of – • Public Hearing #1: December 11, 2019 GWMP development; • Targeted Stakeholder Meeting: February 13, 2020 • Consult with interested stakeholders and the general public throughout the GWMP development process; • Public Workshop #1: February 20, 2020 @ 5:30pm‐7:30pm • Involve stakeholders in determining the planning goals and • Draft GWMP for public review: Late April 2020 objectives; • Public Workshop #2: May 2020 • Collaborate with stakeholders to include their recommendations and • Final GWMP draft: Mid‐Summer 2020 concerns, where feasible; and • Empower the Little Lake Valley Groundwater Basin to develop a • Public Hearing #2: August 2020 sustainable and manageable GWMP for the future.
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Area Affected by GWMP Required Components
• Basin Management Objectives (BMOs). • Monitoring and management of: • Groundwater levels; • Groundwater quality; • Inelastic land subsidence; and • Changes in flow and quality of surface water that directly affect groundwater or groundwater pumping that affects surface water flow or quality. • Description of how recharge areas identified in the plan substantially contribute to the replenishment of the groundwater basin.
Required Components, continued Example Groundwater Management Goals
• Plan to involve other agencies that enables the local agency to work • Ensure a Reliable Water Supply. cooperatively with other public entities whose service area or boundary overlies the groundwater basin. • Ensure Long‐Term Groundwater Sustainability. • Maps that detail the following: • Optimize Conjunctive Use of Surface Water and Groundwater. • Area of the groundwater basin; and • Protect Water Rights. • Recharge areas for the groundwater basin. • Adoption of monitoring protocols designed to detect changes in: • Prevent Unnecessary Restrictions on Groundwater Use. • Groundwater levels • Groundwater quality • Inelastic surface subsidence; and • Flow and quality of surface water that directly affect groundwater levels or quality or are caused by groundwater pumping in the basin.
Voluntary Components
• Control of saline water intrusion • Identification and management of wellhead protection areas and recharge areas. • Regulation of the migration of contaminated groundwater. • The administration of a well abandonment and well destruction program. • Mitigation of conditions of overdraft, if applicable. • Replenishment of groundwater extracted by water producers. Questions and Open Discussion • Monitoring of groundwater levels and storage. • Facilitating conjunctive use operations. • Identification of well construction policies. • The construction and operation by the local agency of groundwater contamination cleanup, recharge, storage, conservation, water recycling, and extraction projects. • The development of relationships with state and federal regulatory agencies. • The review of land use plans and coordination with land use planning agencies to assess activities which create a reasonable risk of groundwater contamination.
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Little Lake Valley Groundwater Management Plan Public Workshop
February 20, 2020 @ 5:30pm – 7:30pm City Hall – City Council Chambers 111 E. Commercial St., Willits
AGENDA
1. Opening Remarks and Introductions
2. Presentation on the Groundwater Management Plan (GWMP) Development Process
a. Meeting Purpose
b. Background
c. What is a GWMP?
d. Area Affected by GWMP
e. Example Groundwater Management Objectives
f. Required Components
g. Voluntary Components
h. Public Outreach Objectives
i. Public Input Forums
j. Public Communication and Notification Methods
k. Plan Development Schedule
3. Questions and Open Discussion
Please contact us at: [email protected] with any questions/comments/information. 5/1/2020
LITTLE LAKE VALLEY GROUNDWATER What is a Groundwater Management Plan?
MANAGEMENT PLAN • Voluntary, non‐regulatory plan subject to the Groundwater Public Workshop Management Act. • NOT subject to the Sustainable Groundwater Management Act (SGMA). February 20, 2020 • General guidelines for local understanding and management of Presented by LACO Associates groundwater resources. on behalf of the City of Willits • NO inherent implementation authority. Rodney Wilburn, PE – LACO Rebecca Dalske – LACO • Tool to identify future actions that can be taken to sustainably Jordan Blough – LACO manage groundwater. Andrea Trincado – City of Willits
Meeting Purpose Background
• Provide overview of the Groundwater Management Plan (GWMP) • City of Willits awarded ~$500,000 in Prop 1 grant funding through goals and intentions. DWR for well improvement project. • Receive input and information on the history of groundwater • GWMP is condition of grant funding. management in the Little Lake Valley. • GWMP must be adopted by September 6, 2020. • Solicit public input regarding the plan components and goals. • City Council contracted with LACO Associates to prepare the GWMP.
Area Considered in GWMP Area Considered in GWMP
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Required Components Example Groundwater Management Per Section 10753.7 of the Water Code Objectives • Basin Management Objectives (BMOs). • Objectives that set forth the priorities and measurable criteria of local • Ensure a reliable and sustainable water supply. groundwater basin management. • Optimize conjunctive use of surface water and groundwater. • What are our goals and how do we measure success? • Monitoring and management of: • Maintain and protect historic groundwater uses. • Groundwater levels; • Protect groundwater quality. • Groundwater quality; • Inelastic land subsidence; and • Flow and quality of surface water that directly affect groundwater levels or quality or are caused by groundwater pumping in the basin. • Adopt monitoring protocols.
Required Components, cont. Public Outreach Objectives Per Section 10753.7 of the Water Code • Identify recharge areas to replenish the groundwater basin. • Inform the public regarding the process for – and progress of – GWMP development; • Plan for stakeholder involvement. • Consult with interested stakeholders and the general public • Maps of the following: throughout the GWMP development process; • Area of the groundwater basin; and • Involve stakeholders in determining the planning goals and • Recharge areas for the groundwater basin. objectives; • Collaborate with stakeholders to include their recommendations and concerns, where feasible; and • Empower theLittleLakeValleyGroundwaterBasintodevelopa sustainable and manageable GWMP for the future.
Public Input Forums* Public Communication and Notification • Willits City Council Meetings (2) Methods* • Public Hearings • Public Opinion Survey –hard copies and electronic versions available; • Public Workshops (2) • Informational discussions with any interested members of the public • Press Releases; • Targeted Stakeholder Meetings (2) • Email List; and • Composed of resource agency representatives, representatives from adjacent public agencies, and landowners in existing contractual water use • Website. relationships with City *See Public Outreach Plan (available through City of Willits website) for further *See Public Outreach Plan (available through City of Willits) for further details on details on outreach methods outreach methods
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Plan Development Schedule
11 December 2019 20 February 2020 Mid‐May 2020 July 2020
Public Hearing #1 Public Workshop #1 Targeted Stakeholder Final GWMP draft Meeting #2 Questions and Open Discussion
Targeted Stakeholder Draft GWMP for public Meeting #1 review Public Workshop #2 Public Hearing #2 13 February 2020 May 2020 Late‐May 2020 August 2020
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