House Natural Resources committee advances slate of water bills; fiercest debate over accepting older water analyses with 15% cut

The House Natural Resources, Energy and Water Committee on Oct. 12 advanced a package of bills addressing groundwater modeling, developer demand estimates and water-technology research, but the most heated debate centered on Senate Bill 11-14, which would allow certain pre-May 31, 2023 analyses of assured water supply to be accepted if the holder submits a sworn statement reducing the analysis volume by 15% before converting the analysis to a certificate.

Why it matters: Committee members and stakeholders said the bills could affect the pace of housing development, the replenishment obligations of groundwater districts and how the Arizona Department of Water Resources (ADWR) evaluates and responds to new modeling information. Opponents warned some measures could undercut protections in the state’s groundwater framework by allowing older or outdated analyses to be used in approvals.

Senate Bill 11-14: accept-old-analyses-with-cut Senate Bill 11-14 passed the committee on a 5–3–2 vote after extended testimony from the bill sponsor, Senator Tim Dunn, developers and water agencies. Senator Dunn, sponsor for Legislative District 25, described the measure as a way to reduce “stranded investment” and to restore positive balance in the Phoenix model by applying a uniform 15% reduction to previously issued analyses before conversion to certificates. He said the reduction is taken at conversion: "when you convert to a certificate … my thousand (acre-feet) take off 15%… now I'm only gonna get 850," he said.

Central Arizona Project (CAP) and the Groundwater Replenishment District (GRD) opposed the bill in testimony, saying the measure could add hundreds of thousands of acre-feet to future replenishment obligations if outdated analyses are accepted. Jeff Gray of CAP told the committee the bill could increase GRD obligations by roughly 250,000–300,000 acre-feet and noted the GRD’s current annual replenishment obligation is about 35,000 acre-feet.

ADWR staff (Trent Blomberg and others) said they were neutral on the bill but cautioned that the assured-water-supply program includes multiple criteria beyond physical availability and urged further technical work before the measure is finalized.

Senate Bill 11-15: demand calculator updates Senate Bill 11-15, passed 5–4–1, would require the ADWR director to adopt rules updating the department’s project demand calculator and to update those rules every five years; the bill also permits expedited rulemaking. Spencer Camps, representing the Home Builders Association of Central Arizona, said the demand calculator is a voluntary spreadsheet-type tool developers use to estimate project water needs and that it was last fully updated in about 2015. "It's a tool. Applicants can submit a demand calculator of their own choosing," said Chuck Womberg, Legislative Liaison for ADWR, who said ADWR is working on an update and has concerns about putting a specific tool in statute because that could reduce flexibility for applicants.

Senate Bill 11-16: alternative model notification Senate Bill 11-16, also advanced (vote 5–4–1), requires ADWR to send a written receipt within five days after receiving an alternative groundwater model and to notify the submitter in writing within 60 days whether the department accepts the model’s overall findings and to explain any rejections of specific findings. ADWR staff said they are neutral and noted model reviews can be complex, often involve back-and-forth with applicants and can stop the statutory clock while deficiencies are addressed; the department expressed concern that a strict 60-day deadline could be impractical for complex model reviews.

Senate Bill 15-18: transfers of integrated-grandfathered rights in subsequent AMAs Senate Bill 15-18, which passed 5–4–1, would allow holders of integrated grandfathered rights (IGFRs) in a subsequent Active Management Area (AMA) to not irrigate part of their land and to transfer, lease or sell the associated water duty to another irrigator in the subsequent AMA, provided the director is notified. ADWR expressed concerns that allowing wholesale transfer of IGFR duties could undermine conservation goals in AMAs designed to protect stressed aquifers. Ben Altschneider of ADWR described the historical bargain that AMAs allow continuation of existing irrigation subject to conservation and restrict expansion of irrigated acreage.

Senate Bill 13-93 and Senate Bill 15-58 Senate Bill 13-93 (due pass, vote 5–4–1) would bar owners of subdivided land from being required to provide or pay for a water source as a condition of receiving a shared water supply designation or written commitment of water service, with stakeholders negotiating clarifying language to limit the provision to the ADOS process. Senate Bill 15-58 (due pass, vote 6–3–1) would create a temporary Water Technology Study Committee to research existing and future water-saving technologies and return a report by Dec. 30, 2026; members would include ADWR, the Water Infrastructure Finance Authority and academic and municipal representatives.

Appropriation: Senate Bill 14-48 Senate Bill 14-48, an appropriation of $10 million from the state general fund to the On-Farm Irrigation Efficiency Fund for fiscal year 2026 (exempt from lapsing), passed with a corrected vote of 8–1–1. Committee members praised on-farm projects that reduce water use and increase crop yields.

Votes at a glance - Senate Bill 11-14 (accept pre-5/31/2023 analyses if holder submits sworn statement reducing remaining volume by 15% before certificate conversion): passed, 5 ayes, 3 nays, 2 absent. Sponsor: Sen. Tim Dunn. Key concerns: potential large increase in GRD replenishment obligations; multiple AWSP criteria beyond physical availability. - Senate Bill 11-15 (require ADWR to update the project demand calculator rule every 5 years; expedited rulemaking permitted): passed, 5 ayes, 4 nays, 1 absent. Key details: ADWR said the demand calculator is a voluntary tool last fully updated ~2015 and is being revised; agency cautioned about codifying a specific tool. - Senate Bill 11-16 (notice and 60‑day written response requirement for alternative groundwater models): passed, 5 ayes, 4 nays, 1 absent. ADWR flagged complexity and potential strain on staff; licensing time frame for AWS reviews noted as 210 days. - Senate Bill 15-18 (allow transfer/lease/sale of IGFR-associated water duty in subsequent AMAs with notification): passed, 5 ayes, 4 nays, 1 absent. ADWR cautioned transfers could undermine AMA conservation objectives. - Senate Bill 13-93 (limit conditioning of shared water supply designation on owner paying replenishment obligation — clarification to apply to ADOS process requested): passed, 5 ayes, 4 nays, 1 absent. - Senate Bill 15-58 (create Water Technology Study Committee; report due Dec. 30, 2026): passed, 6 ayes, 3 nays, 1 absent. - Senate Bill 14-48 ($10 million appropriation to On-Farm Irrigation Efficiency Fund, FY2026): passed, corrected vote announced 8 ayes, 1 nay, 1 absent.

Discussion versus decisions Committee action produced formal “due pass” recommendations on all bills listed above. The committee record shows extended policy and technical discussion (models, demand-calculator assumptions, agency review timelines) that stopped short of final statutory drafting on several technical points; ADWR repeatedly signaled willingness to continue discussions with sponsors before floor action. Several members urged further amendments (including possible COW/caucus amendments) to resolve implementation details, especially for SB 11-14.

What’s next All bills advanced with the committee’s due-pass recommendations and will proceed toward floor or subsequent committee action as required. Several sponsors and ADWR staff said technical and drafting follow-up is expected before final passage.

Ending note Committee members, industry representatives and ADWR repeatedly emphasized the policy tradeoffs between facilitating development and protecting long-term groundwater supplies; several stakeholders called for continued negotiation on technical fixes before the measures reach final floor votes.