Groundwater fills irrigation ditch on a Kern County cotton field in the 2015 drought. Photo by Chris Austin/Maven’s Notebook

By Thomas Harter, Vicki Kretsinger Grabert and Tim Parker

A group that helps shape California groundwater policy has proposed several ideas for state consideration in implementing the 2014 Sustainable Groundwater Management Act (SGMA).

The Contemporary Groundwater Issues Council of the Groundwater Association of California – comprised of various agency executives and influential water researchers and consultants – weighed in on three major issues the California Department of Water Resources (DWR) will face in the next 18 months as it drafts the law’s regulations and guidelines:

• Criteria for DWR evaluation of Groundwater Sustainability Plans (GSPs)
• Best Management Practices (BMPs) for sustainable groundwater management
• Tools and technologies that DWR needs to provide to local Groundwater Sustainability Agencies (GSAs) for effective implementation of the law.

The council developed the recommendations earlier this summer after inviting officials at DWR and the State Water Resources Control Board to present their ideas and plans for the law’s implementation

1. Evaluating sustainability plans

By mid-2016, DWR will have set regulations on the evaluation and implementation of GSPs (Figure 1 below). The council addressed several topics relevant to drafting those rules, mainly:

• How to assess: (1) appropriateness of a GSP, (2) metrics for measuring success, (3) integrating the required 50-year planning horizon and (4) public outreach and stakeholder engagement in the GSP process
• How to address cross-basin boundary challenges

Council members’ concerns included:

• Making regulations sufficiently flexible for a highly variable and somewhat subjective process while being firm on attaining sustainability goals
• Some regions missing the mandatory deadline for completion of GSPs because they were politically challenged and slow to form GSAs.
• DWR’s ability to provide GSAs the technical assistance needed to develop acceptable plans
• Lack of adequate data in some basins to prepare adequate GSPs
• Timeliness of DWR’s GSP reviews
• Constitutional restrictions imposed by California’s Proposition 218 – a 1996 voter-approved initiative – may impede GSA financing

Evaluating GSPs

2. Best Management Practices for achieving sustainability

The law requires DWR to publish Best Management Practices (BMPs) by Dec. 31, 2016. Issues for consideration include:

• Infrastructure approaches to increase recharge and decrease groundwater demand
• Assessment of BMPs’ effectiveness
• Data needs
• Technical/financial/regulatory support to advance implementation of programs and practices
• Outreach and education

Concerns include:

• How regulations would address data confidentiality
• Availability of technical assistance to facilitate effective implementation of BMPs
• Standardizing data collection, monitoring and modeling/assessment to ensure attainment of basin objectives without being overly prescriptive
• Quality assurance and control (QA/QC) in data collection, reporting and assessment
• Availability and adequacy of staff and expertise

Best Management Practices

3. Tools and technologies for effective implementation

The success of the new groundwater law depends in part on providing local agencies useful tools and technologies for developing and implementing the GSPs.

For economies of scale it may be more advantageous that the state provide the big data tools. These would include INSAR (Interferometric Synthetic Aperture Radar) to evaluate the effects of groundwater extraction on land subsidence; SEBAL (Surface Energy Balance Algorithm for Land) for mapping evapotranspiration; and other remote sensing and advanced monitoring techniques. The state also has basin-wide models that can be improved and used for water budgeting and to verify sub-basin and other area-specific models.

The council raised some of the same concerns as in topic 1 and 2 – cost, balance of flexibility vs. effectiveness, need for data QA/QC and lack of data – plus one more: Losing coherency and transparency in data collection by dispersing the effort among too many agencies. The concern is over local agencies’ willingness to share data and conform to electronic formats compatible with statewide databases.

Tools and Technologies

Thomas Harter is a groundwater specialist with the UC Davis Center for Watershed Sciences. Vicki Kretsinger Grabert is president of Luhdorff & Scalmanini Consulting Engineers in Woodland, Calif., and Tim Parker is president of Parker Groundwater in Sacramento. Harter and Parker are on the board of directors of the Groundwater Resources Association of California and Grabert is a former board member.

Figure 1: Summary of SGMA regarding DWR regulations for GSPs

Figures 2: Excerpts from SGMA on best management practices and assessment of water available for groundwater replenishment