Discussion Paper. GROUNDWATER DATA IN THE SGMA CONTEXT Identifying Groundwater Data Needs, Challenges and Potential Solutions

Transcription

1 Discussion Paper GROUNDWATER DATA IN THE SGMA CONTEXT Identifying Groundwater Data Needs, Challenges and Potential Solutions Prepared by: Tara Moran and Janny Choy This report was prepared as background information for the second workshop in a four-part series focusing on groundwater data in the SGMA context. This series is hosted by Stanford University s Water in the West Program and the Gould Center for Conflict Resolution, in conjunction with California State University Sacramento s Center for Collaborative Policy at Stanford University. January 28-29, 2016

2 Table of Contents 1 Introduction to Groundwater Management in California Workshop Objectives Data Requirements under SGMA... 5 Box 1. Avoiding Undesirable Results under SGMA Box 2. Groundwater-Surface Water Connectivity in California 4 Summary of Groundwater Data Survey Results References Additional Reading on Groundwater-Surface Water Interactions... 8 Cover photos courtesy of the Bureau of Reclamation, Chris Austin, and DWR, 2015/Kelly M. Grow. 2

3 1 Introduction to Groundwater Management in California Groundwater is critical to California s well being. It provides 40 to 60 percent of the state s water supply, contributes to stream flow, and supports a diversity of plants and animals. California s aquifers also store a great deal of water about an order of magnitude more than total surface storage combined (DWR 2003). These underground reservoirs are typically referred to as reserves for use during times of scarcity. However, four years of extreme drought combined with a long-term overreliance on the resource have left groundwater levels in most groundwater basins in the state at all-time historical lows (DWR 2014). Despite groundwater s importance to the state s water supply system, the state lacked a comprehensive regime for regulating the resource 1 until passage of the Sustainable Groundwater Management Act (SGMA) in SGMA provides a statewide framework for the monitoring and management of California s 515 alluvial groundwater aquifers. The legislation requires all high- and medium-priority groundwater basins listed in California Department of Water Resources (DWR) Bulletin 118 to be managed under a groundwater sustainability plan (GSP) by January 31, Of the 515 basins identified in Bulletin 118, 43 are classified as high-priority and 84 as medium-priority. Taken together, these 127 basins encompass approximately 96 percent of groundwater use and 88 percent of population in the state (DWR 2014). Remaining basins are classified as low- or very lowpriority. 3 Prior to passage of SGMA, groundwater management in California was a patchwork of local management arrangements. The lack of a comprehensive framework has resulted in fragmented management. Groundwater in California is currently managed by approximately 2,300 independent local agencies (Nelson, 2012). Despite having overlapping jurisdictions or adjacent boundaries, many water management agencies do not coordinate groundwater data or management efforts, resulting in management fragmentation, inefficiency, difficulty in evaluating watershed-scale impacts, competition for limited state funding and technical assistance, and inconsistency in planning (Blomquist 1992; Heikkila 2004; Gerlak and Heikkila 2011; Nelson 2012). Previous efforts to address this fragmentation have been limited by the voluntary nature of groundwater management programs (e.g., the Integrated Regional Water Management Program, AB 3030, AB1938) and the lack of consistent resources (Hughes and Pincetl 2014). Implementation of SGMA provides water managers and the state with a unique opportunity to achieve sustainable groundwater management and ensure long-term protection of this critical resource. In many cases, SGMA will require actions that have been necessary for many years, or in some cases decades, but have not been politically feasible without a state mandate. The formation of Groundwater Sustainability Agencies (GSAs), the agencies responsible for the development and implementation of GSPs, will itself be a difficult task. It will require local agencies to make difficult decisions upfront about who will govern as the GSA, and hence be responsible for developing, implementing, and enforcing the GSP. 1 With exception to adjudicated groundwater basins and special act districts of the state s high- and medium-priority basins are subject to critical conditions of overdraft and must be managed under a GSP by January 31, Low and very low-priority basins must develop a Groundwater Sustainability Agency (GSA) or report groundwater extractions annually, but are not required to develop and implement a Groundwater Sustainability Plan (GSP) (Cal. Water Code ). 3

4 These entities will also have to work collaboratively to ensure that GSPs are coordinated, while incorporating the uncertainty of changing land use practices, water supply, population growth, climate change and other factors over the 50-year planning and implementation horizon defined in SGMA. Successful implementation of SGMA will require a detailed understanding of existing groundwater conditions in each basin, the development of measurable objectives to address undesirable results, and the ability to evaluate progress toward those objectives. Developing groundwater data collection and management protocols that support decisionmaking are crucial for effective and sustainable groundwater management. 2 Workshop Objectives Stanford University s Water in the West Program and the Gould Center for Conflict Resolution, in partnership with California State University s Center for Collaborative Policy, are undertaking a data workshop series with water managers, groundwater consultants, water lawyers, facilitators, state agency officials, academics, NGOs and others to seek solutions to the challenges that water agencies are likely to face in integrating data and water planning tools under SGMA. The goals of the data workshop series are: 1) To exchange information and promote open discussion regarding groundwater data needs, and the best available science and technology to meet these needs. To use this information to support the development of regulations and best management practices under SGMA and to support local agencies during the development of groundwater sustainability plans required under the Sustainable Groundwater Management Act (SGMA). 2) To identify the major data-related issues or challenges state and local agencies are likely to face during SGMA implementation and potential solutions to address these challenges. The workshop series will discuss these topics during four workshops covering (1) groundwater models (November 16, 2015), (2) groundwater data and groundwater-surface water interactions (January 28-29, 2016), (3) decision support tools (June 3, 2016) and (4) geophysical methods (October, 2016). This report is intended to inform the second workshop in the series. The first half of this one and one half day workshop will focus on a new legislative requirement under SGMA groundwater-surface water connectivity. The legal, regulatory, and environmental considerations of the surface water and groundwater connection will be explored, along with approaches and methods for measuring and monitoring these interactions. The second half of the workshop will explore 1) the key data needs and challenges that local agencies are likely to face during implementation of the new groundwater legislation, 2) approaches to integrating and coordinating data at a variety of scales, 3) issues of data transparency, and 4) potential solutions and next steps to address these data-related challenges. This workshop series is taking place while the Department of Water Resources (DWR) is drafting regulations for implementing and evaluating GSPs under SGMA. While part of a broader research program, discussions at this workshop series may help to inform regulation development. 4

5 To inform this workshop series, a groundwater data survey was conducted during the fall of The survey targeted local agency staff 4 and groundwater consultants with the goal of developing a more comprehensive understanding of the current state of groundwater data collection, use, and sharing practices across the state, as well as the role that groundwater models and advanced technologies play in groundwater management decisions. Key findings from the groundwater data survey are presented in Section 4. A groundwater data survey report can be found here. 5 3 Data Requirements under SGMA GSA formation is currently underway in many parts of the state. Once formed, GSAs will need to develop GSPs, which must avoid undesirable results (Box 1) and achieve sustainability goals within 20 years of plan adoption. 6 Improving data collection and understanding about groundwater is an explicit intent of SGMA (Cal. Water Code (f)). Box 1. Avoiding Undesirable Results under SGMA SGMA requires GSA to manage their basin in a manner that does not cause undesirable results, which are defined in the legislation as: one or more of the following effects caused by groundwater conditions occurring throughout a basin: 1. Chronic lowering of groundwater levels indicating a significant and unreasonable depletion of supply if continued over the planning and implementation horizon. 2. Significant and unreasonable reduction of groundwater storage. 3. Significant and unreasonable seawater intrusion. 4. Significant and unreasonable degraded water quality, including the migration of contaminant plumes that impair water supplies. 5. Significant and unreasonable land subsidence that substantially interferes with surface land uses. 6. Depletions of interconnected surface water that have significant and unreasonable adverse impacts on beneficial uses of the surface water. Groundwater data and the development of robust groundwater monitoring and management protocols are a key component in GSP development (Cal. Water Code ). The new groundwater legislation requires GSPs to include data on recharge areas, groundwater levels, groundwater quality, subsidence, and groundwater-surface water interaction (Cal. Water Code ). Agencies must also develop monitoring protocols designed to generate information that promotes efficient and effective groundwater management (Cal. Water Code (f)). These monitoring protocols focus specifically on detecting changes in groundwater levels, water quality, land surface subsidence, and flow and quality of interconnected surface waters. Additional plan elements on saline water 5 Find the complete groundwater data survey report at of the state s high and medium priority basins are subject to critical conditions of overdraft and must be managed under a GSP by January 31, All remaining high and medium priority basins have until January 31, 2022 to be managed under a GSP. 5

6 intrusion, wellhead protection areas, contaminant transport and remediation efforts, well construction and/or destruction policies, conservation efforts, conjunctive use or underground storage, and impacts on groundwater-dependent ecosystems are required where applicable. In basins developing more than one management plan, coordination is required to ensure that the same data and methodologies are used in all the plans. This includes data on groundwater elevation, groundwater extraction, surface water supply, total water use, change in groundwater storage, water budget, and sustainable yield (Cal. Water Code ). Given the existing fragmentation in groundwater management in California, this basin-scale coordination of data and groundwater planning tools will be a major undertaking requiring new approaches, tools and technologies. Box 2. Groundwater-Surface Water Connectivity in California California water law views and regulates surface water and groundwater as separate entities, contrary to science. The new groundwater legislation for the first time requires the agencies managing groundwater to address the impacts of groundwater pumping on surface waters. The California Department of Water Resources is currently in the process of drafting regulations for implementing and evaluating GSPs under SGMA. Because groundwater and surface water connectivity was not necessarily a common consideration in local groundwater management, there are inadequate data in many groundwater basins pertaining to groundwater and surface water interactions. In many cases, there is no information on whether connectivity even exists. According to survey results of California water practitioners, only 38 percent of respondents collect data on groundwater and surface water connections, while 20 percent collect data on groundwater-dependent ecosystems. Our workshop first examines the environmental, legal, and regulatory considerations of groundwater and surface water connections, including how other western states have addressed such interactions. It then explores several approaches, tools, and methods for measuring and monitoring streamflow depletions. Groundwater-Surface Water Interactions under SGMA Under SGMA, a groundwater sustainability agency must consider the interests of all beneficial uses and users of groundwater, including environmental users of groundwater, and surface water users, if there is a hydrologic connection between surface and groundwater bodies (Cal. Water Code (e) and (f)). At its core, SGMA requires GSAs to avoid the six undesirable results (Box 1). SGMA requirements pertaining to surface water and groundwater connectivity include at least two undesirable results. The first is the chronic lowering of groundwater levels that result in significant and unreasonable depletion of supply (Cal. Water Code 10721(w)(1)). In addition to affecting surface water rights holders, a reduction of supply may impact groundwater-dependent ecosystems and other environmental users. The second undesirable result is depletions of interconnected surface water that have significant and unreasonable adverse impacts on beneficial uses of the surface water (Cal. Water Code 10721(w)(6)). Of note, the term interconnected surface water is not defined in the legislation; policy from the Department of Water Resources could help clarify the legislative intent. In addition to avoiding undesirable results, SGMA requires GSPs to include impacts on groundwater-dependent ecosystems where appropriate (Cal. Water Code (l)) and to develop monitoring and management protocols to detect changes in surface flow and surface water quality that directly affect groundwater levels or quality or are caused by groundwater extraction in the basin (Cal. Water Code (d)(2)). 6

7 4 Summary of Groundwater Data Survey Results In the summer of 2015, Stanford University s Water in the West Program and The Gould Center for Conflict Resolution conducted a groundwater data survey. The survey targeted local agencies and groundwater consultants with the goal of developing a more comprehensive understanding of the current state of groundwater data collection, use and sharing practices across the state, as well as the role that groundwater models and advanced technologies play in groundwater management decisions in California. A more complete summary of survey results can be found here. 7 Key findings from the survey suggests that: 1. Groundwater data is often inadequate for decision-making purposes. Despite the fact that more than 80 percent of survey respondents collect groundwater levels data, only slightly more than half consider the geographic coverage (54 percent) and monitoring frequency (56 percent) of these data to be adequate for decision-making purposes. Similar results are observed with water quality data. In this case, 76 percent of survey respondents collected water quality data in their jurisdictional area, but less than half of survey respondents considered the geographic (44 percent) and monitoring frequency (40 percent) of these data to be adequate for decision-making purposes. 2. Many data necessary for effective groundwater management are missing or highly uncertain. Survey respondents indicated that missing or highly uncertain datasets hinder their ability to manage effectively. Missing or uncertain datasets included groundwater recharge potential (38 percent), the location of groundwater recharge areas (28 percent), sustainable yield (36 percent), groundwater-dependent ecosystems (26 percent), groundwater extractions (24 percent) and groundwater levels (22 percent). 3. Many local agencies do not have dedicated groundwater monitoring wells. Some 12 percent of respondents with established groundwater monitoring networks did not have a single dedicated monitoring well in their network. Production wells accounted for 54 percent of the wells in dedicated groundwater monitoring networks. 4. Groundwater management agencies need more data that can be readily shared at a variety of scales. Nearly 60 percent of survey respondents to an open-ended survey question indicated the need for standardized data collection methods and a common data-sharing platform. 5. Local agencies rely on data from other agencies (local, state and federal) to supplement data collected in their jurisdictional area. Groundwater level, water quality, land use data and geology are the data most commonly shared between local agencies. Some 62 percent of survey respondents report using groundwater level and water quality data from other local agencies. Local agencies also rely on state and federal agencies for a breadth of data, including groundwater level and water quality data, climate data and geology. 7 Find the complete groundwater data survey report at 7

8 5 References Blomquist, W. A. (1992). Dividing the Waters: governing groundwater in southern California, ICS, Lanham, MD. [DWR 2003] California Department of Water Resources. (2003). California s Groundwater. Bulletin 118, Update 2003, California Department of Water Resources, Sacramento, CA. [DWR 2014] California Department of Water Resources. (2014). Public Update for Drought Response: Groundwater Basins with Potential Water Shortages and Gaps in Groundwater Monitoring, April 30, 2014, California Department of Water Resources, Sacramento, CA. Gerlak, A. K., and T. Heikkila. (2011). Building a Theory of Learning in Collaboratives: Evidence from the Everglades Restoration Program. Journal of Public Administration Research and Theory, 21: doi: /jopart/muq089 Heikkila, T. (2004). Institutional Boundaries and Common-Pool Resource Management: A Compartive Analysis of Water Management Programs in California. Journal of Policy Analysis and Management, 23(1): Hughes, S., and S. Pincetl. (2014). Evaluating collaborative institutions in context: the case of regional water management in California. Environment Planning C: Government and Policy, 32: doi: /c1210. Nelson, R.L. (2012). Assessing local planning to control groundwater-depletion: California as a microcosm of global issues. Water Resources Research, 48: W doi: /2011wr Additional Reading on Groundwater-Surface Water Interactions Barlow, P.M., and S.A. Leake. (2012). Streamflow depletion by wells Understanding and managing the effects of groundwater pumping on streamflow: U.S. Geological Survey Circular (Available at Galloway, D.L., W.M. Alley, P.M. Barlow, T.E. Reilly, and P. Tucci. (2003). Evolving Issues and Practices in Managing Ground-Water Resources: Case Studies on the Role of Science: U.S. Geological Survey Circular (Available at: Reeves, H.M., D.A. Hamilton, P.W. Seelbach, and A.J. Asher. (2013). Ground-Water- Withdrawal Component of the Michigan Water-Withdrawal Screening Tool: U.S. Geological Survey Scientific Investigations Report Prepared in cooperation with the Michigan Department of Natural Resources. (Available at: 8