June 1st, 2026

Indian Wells Valley California

Has anyone seen the Indian Wells Valley Groundwater Authority’s model? It’s missing and goes by the name “DRI 2-D Model”. This is a very important model, and “it vanished”!

The Indian Wells Valley’s Comprehensive Adjudication Phase 2 trial begins on June 8th, 2026. The trial will be held at the Superior Court in Orange County, Judge William D. Claster presiding.

Let us begin.

For over 6 years, even before the Groundwater Sustainability Plan (GSP) was approved by the Department of Water Resources, we’ve been hearing about this model. It calculates the size of the “pie”. To keep this exercise simple and fun, we’ll step through the Introduction of the trial brief filed by the Indian Wells Valley Technical Working Group beginning on page one.

The model is designed to calculate a very important number called the “Safe Yield” and it’s measured in Acre-feet per year. It’s really a very simple concept:

Safe yield is “the maximum quantity of water which can be withdrawn annually from a ground water supply under a given set of conditions without causing an undesirable result,” where the “undesirable result” is “a gradual lowering of the ground water levels resulting eventually in depletion of the supply.” (Pg. 1, TWG Brief)

So, let’s put this model, the DRI 2-D Model, in context. This is what the Comprehensive Adjudication Phase 2 trial is all about. The Safe Yield. That’s it! In the case of the Indian Wells Valley, the Groundwater Authority has been telling us for years that the Safe Yield is 7,650 acre-feet per year.

The Court determines safe yield based on admissible evidence, reliable methodologies, sound hydrogeologic principles, and the Basin’s actual physical behavior under current conditions. Although expert testimony may assist the Court, California law requires that such opinions rest on a foundation that can be examined and evaluated. Where the underlying methodology cannot be tested or independently assessed, the resulting opinion lacks the reliability required for admissibility. (Pg. 1, TWG Brief)

The IWVGA and U.S. rely on a safe yield figure of 7,650 acre-feet per year (“AFY”) derived from a two-dimensional groundwater model (the “DRI 2-D Model”), which has not been produced. (Pg. 2, TWG Brief)

So, what we have in this case is a model, the all-important DRI 2-D Model, that is missing and can’t be tested or independently assessed. Expert opinions based on the model aren’t admissible in court.

The record concerning the missing DRI 2-D Model is particularly troubling. (Pg. 2, TWG Brief)

Well, yes, that is a bit troubling. Why is this important?

“DRI” is the Desert Research Institute. The U.S. Navy commissioned DRI to prepare McGraw et al. (2016)
(Ex. 21), a groundwater modeling report concerning the Basin. As part of that work, the DRI 2-D Model estimated that pre-1920 recharge to the Basin was 7,650 AFY. (Pg. 2, TWG Brief)

OK, so 7,650 has been around for a long time. You’d think they would update the number based on the latest science and observations of underground aquifers and test wells, right? Nope.

DRI’s modeling work for the Navy “became the basis for the [IWVGA’s] efforts to develop [the GSP]” and was transferred to the IWVGA and its GSP contractor, Stetson Engineers (“Stetson”), for that purpose. The 7,650 AFY recharge value calculated using the DRI 2-D Model was embedded in the GSP groundwater model (“2020 DRI Model”), and 7,650 AFY was again held constant in the 2025 update to that model (“2025 DRI Model”). (Pg. 2, TWG Brief)

7,650 was “embedded” in the 2020 DRI Model and was again held “constant” in the 2025 DRI Model. Do you see where this is headed?

The question remains, did anyone think to ask the GA and Stetson Engineers, Steve Johnson, CEO, aka “the Water Manager” for the GA, to produce the original “DRI 2-D Model” so it could be tested and validated to determine if the Safe Yield was actually 7,650 Acre feet per year? To answer to this question, it’s necessary to include the following 2 paragraphs, in full, found on Page 2 of the TWG Brief.

For years, Searles and other Technical Working Group (“TWG”) parties repeatedly sought production of the 2020 DRI Model through Public Records Act requests, related litigation, discovery, depositions, and court proceedings. The requests specifically sought the model itself, all files necessary to run the model, and all modeling information, and DRI and Stetson work product. IWVGA was obligated to identify any responsive materials that were missing, destroyed, or no longer in existence. (Pg. 2, TWG Brief)

Poof, it vanished into thin air!

This is what’s called a “Coverup” Steve Johnson, CEO of Stetson Engineers

At no point did IWVGA disclose that the foundation of the model—the DRI 2-D Model—allegedly does not exist despite having a duty on multiple occasions to disclose that it was missing. Instead, IWVGA repeatedly represented that responsive records existed and asserted privileges and vague federal restrictions, implying the model existed but was being withheld. IWVGA even represented to this Court that the model was being updated. IWVGA’s conduct conveyed a consistent message that the model existed and would ultimately be produced. Only years later—during recent expert discovery—did the TWG parties learn for the first time that the model that calculated 7,650 AFY—the DRI 2-D Model—has allegedly vanished. (Pg. 2, TWG Brief)

It vanished? Can you believe this? We’re just at page 2 folks.

We suggest you read through the Index of the Technical Working Group brief later in order to get the big picture. You can download all of the briefs below. All of the exhibits and the briefs can be found on the IWV Water District’s website: https://www.iwvwd.com/basin-adjudication-important-documents

To Be Continued….