SMC technical advisory committee outlines short- and long-term "action levels" for groundwater declines

The Salinas Valley Sustainable Management Criteria Technical Advisory Committee (SMC TAC) on Thursday presented a recommended procedure for turning groundwater sustainable management criteria into operational "action levels" that would prompt further technical analysis and, if warranted, management actions. The committee framed separate pathways for short-term declines tied to reservoir operations and for longer-term, multi-year declines.

Gus Yates, chair of the SMC TAC, said the group will review annual groundwater data each April using the water‑year annual report and move to a deeper analysis if certain signs appear. "We developed procedures and criteria for each of those," Yates said, describing two distinct issue types: short-term low water levels related to lower-than-average reservoir releases and long-term declines due to broader groundwater‑budget imbalances.

The nut graf: the committee’s approach is intended to give subbasin committees a predictable, data‑driven signal for when to consider demand management or project alternatives. That is intended to help local managers plan rather than wait for state intervention or emergency orders.

Under the SMC TAC recommendation, a short‑term review would escalate if either a drought‑focused reservoir Drought TAC (DTAC) is active or if about 30% of representative monitoring site (RMS) wells show water levels lower than roughly 75% of the way from the measurable objective toward the minimum threshold. If that step is reached the TAC would expand the analysis to alternative wells and assess geographic clustering to inform what kind of management might help.

For longer‑term declines, the TAC recommended using an analysis period of up to about 30 years to estimate trends while avoiding bias from beginning or ending the period on exceptional wet or dry years. The group recommended a nonparametric trend analysis approach (a robust slope/test method) and said an initial threshold for additional review would be if about 35% or more of RMS wells show a declining trend or failure to recover after drought. The TAC stressed examining individual hydrographs to screen for local, nonregional causes (for example, a changed pump or crop in a single well) before concluding a broader trend exists.

Yates described follow‑up steps if long‑term trends appear: compile correlated time series (pumping, land use, crops, rainfall and ET, external groundwater levels in the east‑side subbasins, reservoir operations, or Clark Colony changes), attempt to identify likely drivers, and then provide subbasin committees with locations, magnitudes, and possible causes and recommend actions to begin implementation the following year.

Public commenters emphasized urgency and local consequences. Bill Lipe, identified in the meeting as a Monterey County resident, warned that "you can almost rest assured that demand management is coming to this valley" if local actors delay and DWR steps in. Bill Light, a Monterey County resident who attended the TAC meeting, praised the committee’s work and urged balancing near‑term demand management with longer‑term projects, saying, "Hopefully keep DWR out of here." Tom Bursick, another commenter, urged the committee to note that the California Department of Water Resources (DWR) uses the term "triggers" in its reports and suggested aligning nomenclature if SMC outputs are shared with DWR.

Committee members asked technical questions about choices in the methods and the influence of the 2014–2017 period when reservoir releases were reduced. Nancy Isaacson noted that litigation and a subsequent settlement required minimum releases of 60 cubic feet per second and helped create the DTAC; she said that period likely affected historical records and should be taken into account when interpreting trends.

The TAC said it will test the action‑level approach by applying the methods to the 2024 annual reports and returning results as a pilot to the subbasin committees. The TAC’s next meeting was scheduled for April 9 to review the annual reports and to begin developing additional action levels for storage and subsidence, with water‑quality and interconnected surface‑water action levels to follow after further guidance and analysis.

Ending: The SMC TAC framed its work as a data‑first process: annual screening using defined numeric checks, expanded multi‑site analysis when a threshold is met, causal examination, and then recommendations to subbasin committees about what, if any, management actions to implement the following year. The committee and staff said the goal is to provide growers and other water users earlier notice and technical context so local measures can be taken before state enforcement becomes necessary.