The water Summit
A critical management area, and a plan that runs to 2080
The Parowan Valley aquifer, and the plan that regulates it.
Safe yield for this basin is estimated at 22,000 acre feet a year. Between 2010 and 2019 well withdrawals averaged 35,000 with depletion around 33,000. On 15 October 2024 the State Engineer adopted a management plan requiring that to fall by about 11,000 acre feet a year, curtailing water rights by priority date in four phases between 2043 and 2080.
Start here
Twenty two thousand in, thirty three thousand out.
The Parowan Valley aquifer has been pumped harder than it recharges for a long time, and unlike a good many water arguments this one is not a matter of opinion. The State Engineer estimates safe yield for this basin at 22,000 acre feet a year. Between 2010 and 2019, well withdrawals averaged 35,000 acre feet a year and the depletion resulting from them ran at about 33,000.
That is half again more taken out than the basin can replace, sustained across a decade, and it is why Parowan Valley is formally designated a critical management area. On 15 October 2024 the State Engineer, Teresa Wilhelmsen, adopted a groundwater management plan under Section 73-5-15 of the Utah Code, stating that average actual depletion has to fall by about 11,000 acre feet a year.
Summit, Parowan and Paragonah are all inside it, and about a hundred and sixty square miles of valley floor with them. For a community whose economy is irrigated farm ground, this is the structural fact about what land here is worth.
The arithmetic
22,000
acre feet a year of safe yield
35,000
average annual well withdrawals, 2010 to 2019
33,000
acre feet a year of depletion from them
11,000
acre feet a year the plan has to remove
The mechanism
Priority date, and four dates between 2043 and 2080.
The plan does not ration everybody equally. It curtails water rights by priority: the newest go first and the oldest survive longest, in four phases published in the plan itself.
| Phase | Takes effect | Rights curtailed | Depletion remaining |
|---|---|---|---|
| Now | No regulation | None | About 33,000 acre feet |
| 1 | 1 January 2043 | Priority on or after 1 January 1955 | About 30,000 |
| 2 | 1 January 2060 | Priority on or after 1 January 1954 | About 29,000 |
| 3 | 1 January 2070 | Priority on or after 1 January 1953 | About 27,000 |
| 4 | 1 January 2080 | Priority on or after 5 December 1951 | About 22,000 |
From the plan's own table. After each phase only rights senior to the listed priority date remain authorised to divert. The end point is a basin back at its estimated safe yield, reached in 2080.
Two things about that table are easy to miss. The first is how far away the first phase is: nothing is curtailed until 1 January 2043, which is a long horizon by any standard and considerably longer than the equivalent plan for the Cedar City Valley next door. The second is how little separates the phases at the top end. Between 1955 and 1951 there are four years of priority dates and eleven thousand acre feet of depletion, which tells you how much of this valley's water was claimed in a narrow window in the middle of the last century.
The State Engineer can also move a phase's priority date later, based on artificial recharge or reductions in depletion achieved in the ten years before the target date. In other words the schedule is a backstop rather than a certainty, and a valley that solves part of the problem another way buys itself time.
The date before the dates
Meters, from 2030, on every regulated diversion.
Long before any right is curtailed, something more immediate happens. From 2030, wells and surface diversions in the Parowan Valley that are regulated by the commissioner must install, operate and maintain approved flow measuring devices, conforming to whatever rules the State Engineer sets about installation, operation and how often data is transmitted or use reported. Those devices have to be accessible to the commissioner and to the State Engineer's staff.
That is the practical near term change for anybody farming here, and it is seventeen years earlier than the first curtailment. Measurement is what turns an estimate into an enforceable figure, and it is the step that makes everything after it possible. It is also a cost and an obligation that attaches to the diversion rather than to the person, which means it comes with the land.
Depletion from irrigation will be calculated from an annual crop survey prepared by the distribution system commissioner, tabulating irrigated acreage by crop type across the plan area and published every year in the distribution system report. Municipal depletion is diversion minus return flow. Everything else is assessed individually.
The obligation runs with the water, not with the owner. A metering requirement, a priority date and a curtailment schedule are all attached to the water right rather than to whoever happens to hold it. Buy ground with a 1962 priority date on it and you have bought a right that the published schedule curtails in the first phase. That is not a hidden risk, it is a public record, and it is the single most important thing to check before making an offer on irrigated ground in this valley.
A different basin
This is not the Cedar Valley plan.
The valley immediately south of this one is under its own separate groundwater management plan, adopted on 11 January 2021, with its own safe yield figure, its own phases and its own dates. The two are frequently confused because they are adjacent, both in Iron County and both administered by the same State Engineer. They are different basins under different plans. The Enoch companion covers the Cedar City Valley plan and the ground subsidence that goes with it.
The differences matter to anybody comparing land. Parowan Valley's first curtailment is 2043 and Cedar Valley's is 2035. The priority cut offs, the safe yield estimates and the required reductions are all different numbers. And Cedar Valley has a documented land subsidence and earth fissure problem that does not appear in the Parowan Valley literature at all.
So a water right in this valley and a water right twelve miles south are governed by different schedules, and anybody weighing farm ground in both places needs to read both plans rather than assuming one applies. Both are published by the Division of Water Rights.
| Parowan Valley | Cedar City Valley | |
|---|---|---|
| Plan adopted | 15 October 2024 | 11 January 2021 |
| Safe yield | About 22,000 acre feet a year | About 21,000 acre feet a year |
| First curtailment | 1 January 2043 | 1 January 2035 |
| Final phase | 1 January 2080 | 1 January 2080 |
| Towns inside it | Parowan, Paragonah, Summit | Cedar City, Enoch, Kanarraville and the valley |
| Subsidence and fissures | Not a documented issue in this basin | Documented, with a 2014 state study |
Two adjacent valleys, two separate plans, and the same State Engineer. The similarity of the final dates is coincidence rather than design, and every other row differs.
Keep reading
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Read the guideMoving here
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You are buying land and water, with a house attached.
Read the guideThe companion
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The creek, the aquifer and the divide, in one place.
Read the pageQuick answers
The aquifer, answered.
It has been withdrawing more than it can replace for a long time, which is why the State Engineer designated it a critical management area. Safe yield for the basin is estimated at 22,000 acre feet a year, while well withdrawals between 2010 and 2019 averaged 35,000 with depletion of about 33,000. The management plan adopted in October 2024 exists to bring depletion back to safe yield by 2080, and it does so by curtailing water rights.
On 15 October 2024, by State Engineer Teresa Wilhelmsen, under Section 73-5-15 of the Utah Code. A proposed draft had been released on 6 August 2024. Its stated objectives are to ensure groundwater withdrawals do not exceed safe yield, to safeguard the physical integrity of the aquifer, and to protect water quality in the basin, which covers the drainage area of the Parowan Valley.
The first phase takes effect on 1 January 2043 and curtails rights with priority dates on or after 1 January 1955. Phase two follows on 1 January 2060 at 1 January 1954, phase three on 1 January 2070 at 1 January 1953, and phase four on 1 January 2080 at 5 December 1951. After each phase only rights senior to the listed priority date remain authorised to divert water.
From 2030, wells and surface diversions in the Parowan Valley regulated by the commissioner must install, operate and maintain approved flow measuring devices, conforming to whatever rules the State Engineer sets on installation, operation and reporting, and accessible to the commissioner and the State Engineer's staff. It is thirteen years earlier than the first curtailment and it is the practical near term change for anybody farming here.
The water right and its priority date attach to the right rather than to whoever holds it, so in practice yes, buying irrigated ground here means buying whatever schedule that right sits on. Ground carrying a 1962 priority date is ground whose right the published schedule curtails in the first phase. That is a public record rather than a hidden risk, and checking it is the most important step before an offer on farm ground in this valley.
Yes, and in one direction. The State Engineer may adjust a phase's regulated priority date to a later date based on average annual artificial recharge or on reductions in depletion achieved within the basin during the ten years before the target date. The schedule is therefore a backstop rather than a certainty, and a valley that solves part of the problem another way buys itself time. Voluntary arrangements outside strict priority are also permitted.
No, and confusing the two is easy because they are adjacent, both in Iron County and both administered by the same State Engineer. The Cedar City Valley plan was adopted on 11 January 2021 with its own safe yield figure and its own phases beginning in 2035. Different basins, different numbers, different dates. Cedar Valley also has documented land subsidence and earth fissures, which do not appear in the Parowan Valley literature.
For irrigation, from an annual crop survey prepared by the distribution system commissioner, tabulating irrigated acreage by crop type across the plan area and published every year in the distribution system report. For municipal use it is the groundwater diversion minus return flow from wastewater effluent and from lawn and garden watering. Any other use is assessed individually, with users reporting as the State Engineer directs.
Much less directly, because the plan regulates water rights rather than household taps, and its practical bite is on irrigated agriculture and on anybody with their own well and right. Where it reaches a residential buyer is in land value, in the long term supply position of every community in this valley, and in the specific case of a parcel that carries irrigation shares or a well with a priority date attached to it.
The number that matters is a date, not an acreage.
On irrigated ground in this valley the priority date on the water right tells you more about long term value than the acreage does, and it is a matter of public record. That is a short enquiry and it belongs in the arithmetic before an offer rather than in a conversation after one.