Sustainable Groundwater Management Act: Initial Notification of a Proposed Basin Boundary Modification

Transcription

1 Sustainable Groundwater Management Act: Initial Notification of a Proposed Basin Boundary Modification

2 Proposed Boundary Modification The Butte County Department of Water and Resource Conservation has submitted to the Department of Water Resources (DWR) an initial notification to explore a basin boundary modification. The proposed basin boundary modification is a jurisdictional modification involving a consolidation of the Vina ( ), West Butte ( ), East Butte ( ) and North Yuba ( ) subbasins that lie within Butte County and a boundary adjustment along the Butte County line except for the portion of the Yuba County Water Agency that extends into Butte County. The modification would create a new subbasin called the Butte subbasin or Butte Basin (Figure 1). The Butte subbasin includes the water bearing units of the Tuscan, Laguna, Riverbank and Modesto formations. The Groundwater Sustainability Agencies in the Butte Basin include Butte County, the City of Chico, the City of Biggs, the City of Gridley, the City of Oroville, Western Canal Water District, Richvale Irrigation District, Biggs West Gridley Water District, Butte Water District, Thermalito Water and Sewer District and Butte College. Background The Sustainable Groundwater Management Act (SGMA) went into effect on January 1, There are 127 Bulletin 118 subbasins designated by the California Statewide Groundwater Elevation Monitoring (CASGEM) program as high or medium priority. In these subbasins, Groundwater Sustainability Agencies (GSA) must be formed and take responsibility to develop and implement a Groundwater Sustainability Plan (GSP). A GSA can be formed by a single local public agency, or combination of agencies. If a GSA is not formed by June 30, 2017, the State Water Resources Control Board (SWRCB) will intervene, impose fees and assume management of the basin. There are four subbasins (Vina, West Butte, East Butte and North Yuba) subject to SGMA that are within the boundaries of Butte County. Butte County and most of the other local public agencies in these subbasins have elected to be a GSA. While many decisions lie ahead on governance and GSP development, one of the near-term decisions facing local agencies is whether to request a modification to basin boundaries. In anticipation of the basin boundary modification review, on March 25, 2015, the Butte County Board of Supervisors directed the Department of Water and Resource Conservation (Department) to evaluate whether basin boundaries should be adjusted in a manner that will improve the likelihood of achieving sustainable groundwater management (Resolution ). The Department is proposing a modification to the four subbasins by combining them into a single subbasin that would be bounded within Butte County. The Department is providing initial notice of the proposed basin boundary modification pursuant to Section of DWR s Groundwater Basin Boundaries Regulations (Code of California Regulations Title 23, Division 2, Chapter 1.5, Subchapter 1). P a g e 1

3 Near-term decision: Modify Basin Boundaries The Bulletin 118 subbasins were a reasonable starting point for managing groundwater. However, it is well-recognized that many of the basin boundaries do not reflect hydrogeology or would not foster sustainable groundwater management. As a remedy, SGMA provided local agencies with the ability to request that DWR modify basin boundaries according to regulations [Water Code ]. DWR adopted regulations in November 2015 that prescribe the types of basin boundary modifications, the information required, local agency consultation and the criteria for approval. Local agencies have a variety of options for basin boundary modifications. However, modification requests must be supported by information, justification and meet the criteria for approval. The deadline to submit requests to DWR is March 31, DWR will evaluate requests to determine whether it will promote sustainable groundwater management. DWR may deny a request if it would limit: sustainable groundwater management in the proposed or other basins groundwater storage or recharge in the proposed or adjoining subbasins the coordination of management activities and the sharing of data and information across subbasin boundaries. The formal request to modify a basin boundary must include specific information, data and a demonstration of consultation with local agencies and affected water systems [Groundwater Basin Boundaries Regulations 344]. Additionally, SGMA requires that the GSA consider the interests of all beneficial uses and users of groundwater [Water Code ]. To facilitate coordination and consultation with local agencies and affected systems, the Groundwater Basin Boundaries Regulations ( 343.9) has a process for local agencies to explore possible basin boundary modifications. This paper describes the proposed basin boundary modification and the opportunity to provide input. Providing Input The purpose of the initial notification of a basin boundary modification is to solicit discussion and the opportunity to provide input. The decision of Butte County to formally request a basin boundary modification will be made by the Butte County Board of Supervisors. As part of the Board of Supervisors consideration will be a potential recommendation from the Butte County Water Commission. To meet the March 31, 2016 deadline, a decision by the Board of Supervisors will have to be made by their March 22, 2016 meeting. P a g e 2

4 The input provided by other local agencies, affected systems and interested parties will be a valuable part of the Water Commission and Board of Supervisors consideration. To facilitate local agency consultation and public participation, the Department has: Established a webpage specifically for the basin boundary modification process that can be accessed from the Department s main webpage at: Notified Local Agencies and Affected Systems. The notification is in addition to discussions and meetings held with local agencies and affected systems. Informed interested parties through the January 2016 edition of the WaterSolutions newsletter. Conducted an assessment of local agencies and various stakeholder groups. The assessment report will provide valuable input a range of SGMA implementation topics including basin boundary modification options. Presented the proposed basin boundary modification to the Water Commission at their January 6, 2016 meeting. It is anticipated that the Water Commission will discuss the proposed basin boundary modification options at their February and March meetings. The Department requests that comments including resolutions of support, opposition or modification be submitted by February 15, 2016 by either (BCWater@buttecounty.net) or by mail to Butte County Department of Water and Resource Conservation, 308 Nelson Avenue, Oroville, CA 95965, Attn: Basin Boundaries. Regulatory Effect of Basin Modification Basin boundary modifications can be beneficial to SGMA implementation. However, basin boundary modifications will not change the foundational requirements of SGMA or the necessity to coordinate with adjoining subbasins. Whether basins or subbasins are modified, GSAs will have complex decisions regarding how to best develop, coordinate and implement one or more GSPs for their subbasin or portion of a subbasin. What s required in a subbasin? Establish one or more GSAs. Local agencies have options on how they may structure their GSA within their subbasin. A local public agency or combination of agencies may establish a GSA. For example, if a subbasin includes one or more public agencies (water districts, city and county), they could form a GSA using a joint powers agreement or memorandum of agreement and submit one GSP for all or a portion of a subbasin. Alternatively, each local public agency could designate itself as a GSA and take responsibility for their portion of the subbasin. P a g e 3

5 Develop one or more GSPs. The primary obligation of GSAs is to develop, implement and enforce the GSP. Subbasins could be covered by a single GSP submitted by one GSA, a single GSP submitted by multiple GSAs or multiple GSPs submitted by multiple GSAs. A subbasin is not in compliance until the entire subbasin is covered by one or more GSPs. A subbasin covered by more than one GSP must have a Coordinated Agreement. Under a Coordinated Agreement, the GSAs must coordinate and utilize the same data and methodologies (e.g., groundwater elevation data, groundwater extraction data, surface water supply, total water use, change in groundwater storage, water budget, sustainable yield) for their GSP. Although Coordination Agreements are not required for adjoining subbasins, the regulations governing GSPs will likely have requirements for coordination between adjoining subbasins. Groundwater Sustainability Plan (GSP) Requirements GSPs for the subbasins in Butte County must be submitted to DWR by January 31, Some of the elements of GSPs include a water budget, measurable objectives and interim milestones (every 5 years) that will lead to sustainability in 20 years of adoption and progress reports to DWR and the State Water Board every five years. GSPs must address undesirable results that include chronic lowering of groundwater levels, significant and unreasonable reduction in groundwater storage, significant and unreasonable degradation of water quality, significant and unreasonable land subsidence that significantly interferes with surface land uses and surface water depletions that have significant and unreasonable adverse impacts on beneficial uses of the surface water. An annual report must be submitted to DWR by April 1 st. The specific requirements of GSPs will be subject to regulations DWR is currently developing that will become effective in June, Justification The proposed basin boundary modification is a jurisdictional modification involving a consolidation of the portions of the Vina ( ), West Butte ( ), East Butte ( ) and North Yuba ( ) subbasins that lie within Butte County and a boundary adjustment along the Butte County line except for the portion of the Yuba County Water Agency that extends into Butte County which would be excluded. The modification would create a new subbasin called the Butte subbasin or Butte Basin. The Butte subbasin includes the water bearing units of the Tuscan, Laguna, Riverbank and Modesto formations. Modifying basin boundaries to create the Butte subbasin would promote sustainable groundwater management. The Butte subbasin would provide greater consistency with existing water resource programs (e.g., Groundwater Management Plans, water budgeting, monitoring, CASGEM and public outreach) among the local agencies that have a history of water resource management. A summary of the advantages to the basin modification include: P a g e 4

6 Improving Efficiency Maintaining the existing subbasins presents governance and programmatic complexities for local agencies compared to the proposed modification. Butte County and most of the other eligible local public agencies have elected to be GSAs. In each subbasin, the respective GSAs would have to decide on a governance strategy to implement at least one GSP. There would have to be at least 4 GSP and as many as 27. All four subbasins extend into adjoining counties, not only adding to the number of GSAs, but also requiring new relationships (Figure 2). The result may lead to four unique governance structures that require administration, duplication of data, and redundant public participation processes. The basin modification proposal could result in having one GSP for the Butte Basin. Although maintaining the existing subbasins could work, it would be a departure from nearly a two decade approach on how the local agencies in Butte County have collaborated on water resource management. A preferred approach would be to have a subbasin that builds upon the existing local agency technical and programmatic relationships in Butte County. This approach would reduce the number of distinct GSA governance structures and commensurate GSP planning processes. Some of the specific challenges addressed by the basin boundary modification include: Vina -The Vina subbasin extends into Tehama County. Tehama County has eleven subbasins of which eight are subject to SGMA. Six of the eight SGMA subbasins lie exclusively in Tehama County. The Vina subbasin represents the only subbasin in Tehama County that extensively extends into another county. A very small portion of the Colusa subbasin extends into Tehama County. City of Chico -The City of Chico lies in both the Vina and West Butte subbasins. Without any modification, the City of Chico would have to participate in two different GSP processes. Additionally, the corresponding GSPs could face technical challenges in differentiating the water budget for the City of Chico between the two subbasins. Combining the Vina and West Butte subbasins would put the City of Chico in a single subbasin. Western Canal Water District - The Western Canal Water District (WCWD) overlies the West Butte and East Butte subbasins. WCWD extends into Glenn County. Without any modification to basin boundaries, WCWD would have to be involved in two GSP processes. Their water budget would have to be accounted for separately on a subbasin basis. The proposed basin boundary modification would not resolve having WCWD extend into the basin adjoining the Butte subbasin. A solution could involve retaining the WCWD boundary in the Butte subbasin. This would bring WCWD into one GSP planning unit. P a g e 5

7 West Butte - The West Butte subbasin extends into Glenn and Colusa Counties and is bounded in the west by the Sacramento River. The portion of the West Butte subbasin in Glenn County includes part of the WCWD and unincorporated land. The portion of the West Butte subbasin in Colusa County includes RD 1004 and unincorporated land. The modification along the county line would allow the local agencies in Butte, Glenn and Colusa counties to participate on their respective GSPs. Butte Creek represents the boundary between the West Butte and East Butte subbasins. However, these two subbasins are hydrogeologically connected. Developing a GSP for each subbasin would be highly inefficient. East Butte - The East Butte subbasin extends into Sutter County. It includes unincorporated portions of Sutter County. A small portion of the Biggs West Gridley Water District (BWG) extends into Sutter County. About one third of the Butte Water District extends into Sutter County. Without any changes, the East Butte subbasin would include Sutter County, Sutter Extension Water District and the City of Live Oak. Water management, programs and county ordinances differ between Butte and Sutter Counties. Modifying the basin boundary along the county line will avoid unnecessary conflict and challenges in forming a governance structure. North Yuba - The North Yuba subbasin extends into Yuba County. Honcut Creek is the boundary between Butte and Yuba Counties. The Yuba County Water Agency (YCWA), the Cordua Water Agency and the City of Marysville are the GSAs in the Yuba County portion of the North Yuba subbasin. A small portion of three members of the YCWA extend into Butte County. Water management for these districts is led by YCWA, however, the parcels in Butte County fall under Butte County land use and well permitting jurisdiction. The proposed basin modification would follow the county line bisecting the North Yuba subbasin except where portions of the YCWA member agencies extend into Butte County. In this area, the new basin boundary would follow the YCWA member agencies jurisdictional boundary excluding them from the newly created Butte subbasin. Groundwater Management Plans For over a decade, Butte County, the water districts and the urban water suppliers have administered their respective Groundwater Management Plans, Agricultural Water Management Plans and/or Urban Water Management Plans. The agencies have collaborated on the development and implementation of their respective plans. These plans cover the jurisdictional boundaries of the agencies in a manner consistent with the proposed basin modification. As described in the following section, the basin modification would be consistent with the Basin Management Objective program administered by Butte County on behalf of the entire county. The Basin Management Objective program is not structured by the existing subbasins but rather by the Butte Basin. P a g e 6

8 Butte Basin Groundwater Model/Water Budgets - The basin modification would allow for an efficient utilization of the Butte Basin Groundwater Model (BBGM) for the continued development of water budgets and analysis of basin conditions. In the early 1990s, the Butte Basin Water Users Association (BBWUA) developed the BBGM. The BBGM domain includes the full extent of the four subbasins: Vina, East Butte, West Butte and North Yuba. The BBGM can be a useful planning tool for developing GSPs within these four subbasins. Recent updates to the BBGM include extending the model time period to 2014 to produce water budgets for Butte County. In addition, the updated model uses recent versions of the modeling code, IWFM-2015 and IDC v.4.0. The BBGM provides a technical framework to analyze the four subbasin area as a whole or any defined combination or subset(s) of them. Currently, the BBGM has 34 specified subregions for which water budgets and model outputs can be analyzed. These largely correspond to the County s Basin Management Objectives sub-inventory units. They generally correspond to water district boundaries or areas having similar land or water management characteristics. From the standpoint of governance, this supports analysis and potential reporting requirements based on existing jurisdictional boundaries. Since the model domain encompasses the entire four subbasin area, with minimal effort, the model can be used to analyze any revised subset of the model domain. It can also be used to understand groundwater dynamics between defined sub-regions. This has value for understanding and quantifying groundwater flows between defined subbasins. In addition, data from Urban Water Management Plans are incorporated into the BBGM and distinct sub-regions of the model area corresponding to municipality jurisdictions could be defined. In summary, the BBGM organizes data and provides a framework for the integrated groundwater-surface water system for the four subbasin area. For analysis and reporting purposes, the model domain could be carved up in any number of ways to produce water budgets for newly defined or existing subbasins. Providing Input The Department requests that comments including resolutions of support, opposition or modification be submitted by February 15, 2016 by either (BCWater@buttecounty.net) or by mail to Butte County Department of Water and Resource Conservation, 308 Nelson Avenue, Oroville, CA 95965, Attn: Basin Boundaries. P a g e 7

9 Figure 1: Butte Basin Butte Basin GSAs: Butte County, the City of Chico, the City of Biggs, the City of Gridley, the City of Oroville, Western Canal Water District, Richvale Irrigation District, Biggs West Gridley Water District, Butte Water District, Thermalito Water and Sewer District and Butte College Potential Number of GSPs: 1-11 P a g e 8

10 Figure 2: Existing Subbasins and GSAs P a g e 9