California Water Commission: Critically Overdrafted Basins and Groundwater Sustainability Plan regulations

Draft COD SliderboxDWR’s Mary Scruggs gives more details on the draft list of critically overdrafted basins; plus an update on the development of groundwater sustainability plan regulations

At the August meeting of the California Water Commission, Supervising Engineering Geologist Mary Scruggs briefed the Commission on DWR’s recent release of the draft list of Critically Overdrafted Basins, one of the provisions written into the Sustainable Groundwater Management Act.

In Water Code Section 12924, it says Department will identify basins that are subject to critical conditions of overdraft, so this applies to all the high and medium priority basins under SGMA,” she said. “The ramifications of this are that the basins that are identified as critically overdrafted have to submit their Groundwater Sustainability Plan by January 31st, 2020, which is two years before the other plans are due.”

DWR is using the term ‘critically overdrafted basins’ to refer to what is written in the water code as ‘basins subject to critical conditions of overdraft’ and the designation reflects the actual status and not a potential situation, she said.

In Bulletin 118 released in 1980, 11 basins were identified; the same basins were used for the update in 2003. “The basin boundaries had been changed so this list looks different, but it’s still the same areas that were identified in 1980 – no new issues,” she said.

Mary Scruggs 1Ms. Scruggs then explained how the basins were determined. They began with the development of a base period that would include wet and dry times, consulting with the state climatologist; they also wanted the longest period possible as well as the base period to have the same precipitation as the long-term mean.

Applying it statewide, we did the best we could do, and we ended up having a base period of 1989 to 2009,” she said. “We went back and we evaluated all the basins – not just high and medium; we used groundwater elevation data available at DWR for that time period; come to find out, we had very limited data and there were about 400 basins that we didn’t have data for that time period.”

Ms. Scruggs noted that CASGEM data was not used because CASGEM period data was outside our base period time as it started afterwards, and it was in a drought period; she also noted that drought periods were not included in the base period, per the definition for undesirable results that is in water code section 10721.

Since DWR lacked data in so many places, those basins that were listed in 1980 were kept on the list and local agencies were notified to see if they could provide data to show they weren’t in critical overdraft, and if that data was provided, DWR would do a reevaluation.

We also went back and conducted a review of available reports – DWR reports, region office investigations, USGS reports, published reports, local agency reports, local groundwater management plans and EIRs, and so with that, we wanted to go through and see if we could identify basins with significant and unreasonable impacts as identified under SGMA,” she said. “We reviewed that information to identify these areas of the significant unreasonable undesirable results … we were looking for the very extreme end of critically overdrafted.”

Basins were added to the draft list based on evidence of undesirable results in four areas: chronic lowering of groundwater levels, significant and unreasonable sea water intrusion, significant and unreasonable land subsidence, and significant and unreasonable degraded water quality. “So the basins we’ve identified could have one or more of those undesirable results,” she said.

The preliminary list included all the basins from Bulletin 118-1980, as well as the basins added from the review. In July, DWR staff contacted all the major water districts, the basin managers, and the respective counties of the basins that were on the preliminary list to let them know they had been identified as critically overdrafted and to give them an opportunity to see if they had data that could be used for a reevaluation. Some agencies did provide data and were removed from the list.

There are still a couple we are still waiting to follow up with,” Ms. Scruggs said, “The list that we are releasing today is now our draft list, it should not be a surprise to the basins on the list because they are already aware of it.

Three maps are available: a statewide map and then two maps with more detail by region.


There are 21 basins total,” she said, noting that one basin straddles two DWR regional offices, so the total number on the individual maps will be 22 instead of 21. “All the basins we identified are in the high or medium priority basins under the prioritization, and 21 out of 127 basins total, area wise, it’s about 40% of all the high and medium priority basin area that are our critically identified basins. Breakdown by region, there are no basins in the northern region, one basin in the north-central basin, 16 basins in the south-central region office, and the southern region office has 5 basins.”

Ms. Scruggs noted there are basins that could be overdrafted especially due to the current drought conditions, but the process only identified the severely impacted basins during the base period, 1989-2009.

Next steps:

There will be a public meeting in Clovis on August 25th and a webcast on August 26th which will include more in depth information about our process, the background, the basins identified and the reason for it, as well as the next steps.

Draft list, maps, and more information will be posted on the website: DWR Sustainable Groundwater Management

Public comment period will start after the public meeting for 30 days, ending on September 25. DWR will continue to accept data and information from agencies during comment period. “If there is a basin that’s already on the list that they feel should not be there and we want to see the data to support why it should be taken off the list, or if there’s basins that we don’t have the information and people feel should be listed as critically overdrafted, both ways,” she said. “But we would need that information and that data to be able to support that determination like we did to come up with our original draft list.”

DWR will review comments and data submitted, and revise list as needed; anticipate the list being finalized in October of 2015.

The final list will be published on the website, as well as in the Bulletin 118. “By the water code, we are required to publish that in the Bulletin 118 update in order to make them critically overdrafted basins, so we expect it to be in the Bulletin 118 update coming out in later 2016, but the information that gets published in Bulletin 118 will be the same basins that we finalize come this October and will be on the website.”

Discussion highlights

Commissioner Orth noted that this is relevant because these basins will have to do groundwater sustainability plans by 2020, but the balance of the high and medium priority basins from the CASGEM process have until 2022. “There are now by virtue of this, some high priority designated subbasins that won’t have to do a sustainability plan until 2022, because their high prioritization is not a function of critical overdraft, it’s a function of something else, I don’t know what that is … “

Mary Scruggs clarified. “In the basin prioritization, there were eight criteria that were spelled out in the water code that we did under CASGEM … it would be one category or one criteria out of the eight. Basin prioritization is it’s a prioritization based on importance or groundwater reliance – groundwater use, population, irrigated acreage, a number of wells, so you put all that together. The prioritization that was done under CASGEM is not a reflection on how a basin is being managed, whether it’s being managed well or not being managed well; it’s a reflection of how important groundwater is. … To expect all the high priority basins to come in as critically overdrafted wouldn’t be right, because it’s an importance of groundwater, so if you have a highly important basin and its being managed well, one would not expect it to be critically overdrafted. Ideally we’d like all those basins, none of them to be critically overdrafted.”

But the one part where I do caution is that we looked at it for the base period which is outside the drought,” added Ms. Scruggs. “I expect we may get some comments saying this this is what’s happened, we’ve had four years of drought and it’s dropped here but that’s outside our base period. We’re looking at it outside it and that’s what the code said. That doesn’t mean those areas don’t have problems and it doesn’t mean that the other basins other than the 21 have issues to deal with, but these are the critically overdrafted basins.”

Commissioner Daniels asks about the criteria. “You mentioned chronic lowering of groundwater levels, and ‘significant and unreasonable’ three times, in terms of sea water intrusion, land subsidence, and water quality. I’m wondering how you interpret those terms and what informs your interpretation of those terms, ‘significant and unreasonable’?”

When it comes down to subsidence, you shouldn’t have subsidence, and in the cases that we have, there’s areas that we’re talking 6” to a foot or more of subsidence during the base period, so if you’re seeing that kind of subsidence, they are critically overdrafted and so they got put on the list, assuming it was in the base period,” Ms. Scruggs replied. “Chronic lowering of the groundwater levels; we pull out the data and we look at the hydrographs and to see if groundwater levels are dropping. You would expect that if it’s sustainable or being managed, it would fluctuate and it would fluctuate seasonally or in dry years it could drop down and come back up again, but in the cases, we’re talking over multiple years, it’s not a one year drop … it’s going to vary within the basin because these basins can vary from very large areas, they are deep alluvial aquifers to coastal basins, but it’s the chronic dropping of it. The seawater intrusion, if you have your groundwater dropping, and so your freshwater aquifer would be your groundwater source and you have the sea over here, and if you have groundwater levels dropping and sea water coming in and intruding, that’s a bad thing, too.”

Commissioner Daniels points out that significant and unreasonable are more terms of art …

Ms. Scruggs agreed, and said, “It’s not a matter of is it just barely present … it’s on the extreme end.”

More information …
Can’t make it to the public meeting or webcast?

Maven’s got you covered … I’ll be reporting from the meeting next week, so stay tuned!

A brief update on the Groundwater Sustainability Plan Regulations

Trevor Joseph, Project Manager for the Groundwater Sustainability Plan regulations, updated the Commission on where they are in the development process for this next set of regulations, required to be adopted by June 1st 2016.  He said  DWR is currently in the draft framework phase, meeting with the advisory groups and the public, discussing the issues and challenges. They are receiving input and feedback from the State Water Resources Control Board throughout this process.

They will be drafting the emergency regulations later this fall; they hope to have the draft regulations to the Commission by this December or January.  He noted that the development of these regulations will take more time than the basin boundary regulations as the topic is more complex.

GSP Reg Batch Topics_Page_06With outreach, they have broken the process into smaller topics, as identified on the wheel, and are doing things in three batches so that there can be meaningful discussion. “We want to make sure we give advisory groups and the public an opportunity to really understand what the issues and challenges are we’re hearing, and share those issues and challenges with us,” he said.

Mr. Joseph said they have just completed the second batch of discussion papers and will be holding a webinar next week; they are a few weeks away from releasing the discussion papers on the final topics.

Mr. Joseph then highlighted some of the issues and discussion in the first six topics, noting that it’s hard to go into a lot of details because the discussion papers are fairly dense and the dialog is fairly detailed.

Pre-SGMA conditions and undesired results:We’re spending a lot of time making sure we’re defined sustainability and we understand what baseline means. There are six undesirable results listed in the act: chronic lowering of groundwater elevations, water quality, storage, seawater intrusion, subsidence, surface water depletion, and so we’re spending a lot of time talking about what site specific differences there are in those and the challenge it is from the local level to manage those conditions.”

Measurable Objectives and Interim Milestones:The planning requirements, specifically for SGMA, have to provide measurable objectives and interim milestones to measure progress at every five years. A lot of time here spent making sure we understand how to approach those. How to measure progress is key, especially as it potentially triggers State Board intervention.”

Land use and county involvement:A very important topic that is mainly at the local land use and agency level, but again, very important for the success of SGMA.

Alternative GSP submittals:This is its own separate set of emergency regulations that have to deal with specific opportunities for local agencies that can show that they are already operating sustainably or have a groundwater management plan that is essentially functionally equivalent, there’s the potential that they can use this as an alternative to preparing a groundwater sustainability plan, so we’re talking about the technical requirements that the Department would need to see in order to agree with that sustainability.”

Boundaries, overlapping and fringe areas:This has to deal with overlapping groundwater sustainability agencies and potentially overlapping groundwater sustainability plans. The challenge is created with that, and how to address that potentially in a governance-type requirement in the regulations. Fringe areas is a very unique case where a special act district or an adjudication doesn’t necessarily cover the entire basin or subbasin, so how to handle these little odd fringe pieces that don’t fit within those jurisdictional boundaries. In many cases, they are 5% of the groundwater basin, so what is the appropriate groundwater sustainability plan requirements for those areas? If they are in a high or medium priority basin, they are still required to adhere to the act, but how to approach these areas logically.

Intra-basin coordination agreements: Intra‐basin coordination agreements are agreements that will be formed between two or more GSAs when two or more GSPs are developed within the same groundwater basin; Inter‐basin coordination agreements are agreements that may be formed between GSAs within adjacent, hydrologically connected groundwater basins. “What’s an appropriate type of coordination needed between those hydraulically connected basins? Not within a basin, but the acts of one groundwater sustainability plan shall not interfere with another adjacent groundwater sustainability plan, so we’re talking through that coordination.”

For more information …

Meeting information …

Click here for the agenda and meeting materials.  This was part of agenda item 8, and all of agenda item 9.  Due to webcast streaming issues, basin boundary regulations will be covered at a later date.

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