MINERSVILLE
The dam and the reservoir have different names
Four independent systems will hand you the wrong structure, the dam is private and from 1914, and nobody publishes an agreed figure for how much water it holds.
The water is Minersville Reservoir. The structure holding it is Rocky Ford Dam. Neither name refers to the other, and searching for either one leads somewhere wrong.
| Search for | What you get |
|---|---|
| The dam, by name | The dam inventory files it as "Rocky Ford (Beaver)", which implies what it also holds: a second Rocky Ford in Sevier County |
| Rocky Ford Reservoir, in the names system | Three separate United States features carry that name |
| The Rocky Ford storage station | The soil conservation service does have one, and it is in Sevier County. This reservoir's station is filed under a number, not a name |
| A Minersville dam, in the dam inventory | Two debris dams several miles west, neither of which impounds this reservoir |
And the fishing guidebook resolves it in the simplest possible way: it never mentions the dam at all. The string "Rocky Ford" does not appear anywhere in the 2026 guidebook . The angling public knows this water as Minersville and only as Minersville.
One more thing that is backwards in most descriptions. The reservoir is roughly six miles east of the town it is named after , not west. And the dam's name most likely comes from Rocky Ford Hollow, immediately south of it . No source states that connection, so this page offers it as an observation and not as an explanation.
This is not a Reclamation project and it is not a federal dam. The inventory record is unambiguous :
| Field | Value |
|---|---|
| Owner type | Private |
| Federally regulated dam | No, and every federal agency field empty |
| State regulator | Utah Division of Water Rights |
| Year completed | 1914 |
| Hazard potential | High |
| Last inspected | 21 June 2023 |
| Condition assessment | Satisfactory, dated 1 January 1991 |
This is the same pattern this series found at a privately owned dam two counties north, where a 1991 assessment sat alongside a 2026 inspection. It is the assessment that has not been redated, not a transcription error, because the record carries both dates explicitly.
No rebuild is recorded. The years modified field is empty . This build looked specifically for the kind of spillway driven reconstruction that another reservoir in this series underwent after a dam safety evaluation, and found no agency record of one here. That is a not found rather than a did not happen: the Utah dam safety file that would settle it is closed to automated reading.
Three figures are published for this reservoir's capacity and the two that come from the same federal record differ by a factor of nearly three.
| Figure | What it is called | Source |
|---|---|---|
| 38,733 acre feet | maximum storage | the dam inventory |
| 14,129 acre feet | normal storage | the dam inventory, same record |
| 25,173 acre feet | at the emergency spillway crest, elevation 5,505.0 | the operating company |
This is why there is no percentage on the live strip above. Every other page in this series divides the current storage by a capacity and prints a percentage. Here the denominator is disputed by a factor of 2.7: the same reading would show as 11 percent against one federal figure and 31 percent against the other. A percentage with a denominator like that is not information, it is decoration, so the card beside the storage reading prints the three figures instead.
An observation that is not a resolution. The highest month in the gauge's own recent record is 24,905 acre feet in May 2024 , which is within one percent of the operating company's spillway crest figure. That is consistent with 25,173 being the working full pool and it does not prove it: three years of monthly readings and one high month are not a capacity, and no agency says so.
Eutrophic, and the state says so
A watershed plan that names this reservoir as not supporting the use it is protected for, a mercury advisory only three Utah waters carry, and a reservoir that has lost most of its water.
The Beaver River watershed carries a total maximum daily load, and this reservoir is named in it. The finding, verbatim :
"eutrophic and does not support its designated Class 3A use"
Class 3A is defined in the same document as "Protected for cold water species of game fish and other cold water aquatic life, including the necessary aquatic organisms in their food chain" , and the codified rule puts this reservoir in the Beaver County table at that class . So the state protects this water for cold water game fish and states that it is not currently supporting them.
| Pollutant | Standard |
|---|---|
| Total phosphorus | 0.025 milligrams a litre in lakes |
| Dissolved oxygen | above 4.0 milligrams a litre, one day average |
| Temperature | 20 degrees Celsius |
Read that carefully, because it is not the same as an advisory. This is a watershed plan describing a documented history. It is not a current warning, it does not carry a date for any particular bloom or kill, and it is stronger evidence than an advisory would be, because it is the state describing the condition of the water rather than reacting to a single sample.
Current load 8,906 kilograms of phosphorus a year . The plan gives the load and the standard; this page does not compute a required reduction from them, because the plan states its own and this build did not retrieve it.
Minersville Reservoir carries a fish consumption advisory for wiper, and wiper advisories are rare .
| Species | Mercury | Pregnant women and children | Women of childbearing age | Everyone else |
|---|---|---|---|---|
| Wiper | 0.586 | Do not eat | 1 meal a month | 5 meals a month |
Across the whole state advisory page there are four wiper rows and they sit on three waters: Cottonwood at 0.378, this reservoir at 0.586, and Newcastle twice at 1.395 and 0.685 . Those two are named here because the rarity claim is false without them, and neither is linked, because neither has a page here and sharing a list is not a relationship.
One neighbour on the same page is worth the comparison, though. Navajo Lake sits close by on the same table, carries the same 4/23/18 date, and carries the identical three meal limits, for splake rather than wiper . Two southern Utah reservoirs, different species, same numbers, same day.
And the trap fired here in a new form. One read of the state page enumerated sixty one rows, found this reservoir correctly, and silently dropped the mercury column from every row. A second read, asked directly, returned the figure. Never trust the table; always ask the question.
What a wiper is, and what this page will not say about it. Utah names the species and does not define it in anything retrieved here, so this page does not state its parentage. What is worth noticing is the tension: a warm water hybrid sportfish, in a reservoir classified 3A for cold water game fish, managed under a rule that is entirely about trout. All three of those are agency statements and they do not sit comfortably together.
The shape in the header is traced from the Fathom print artwork, checked against the federal water body polygon .
| Measure | Traced | Federal | Gap |
|---|---|---|---|
| Width against length | 0.7590 | 0.8180 | 7.22% |
| Share of its bounding box | 0.255 | 0.254 | 0.4% |
| Area, stretched on both axes | 1,143.6 acres | 1,139.7 acres | 0.35% over |
| Area, matched on length | 1,061.1 acres | 1,139.7 acres | 6.9% under |
The federal polygon is also the only surface area anyone publishes for this reservoir. It computes to 1,139 acres. The dam inventory leaves its surface area field empty . That is unusual: at the previous lake in this series three agencies published a surface area and the federal polygon disagreed with all of them.
Nearly three miles long and two and a half wide, derived from the federal polygon. No depth is published by anyone, and no mean depth is offered here, because dividing a capacity by an area requires a capacity and this reservoir does not have an agreed one.
Storage comes from soil conservation service station 10238500:UT:BOR, and the card above reads the monthly series because it has no choice .
| Month | Acre feet |
|---|---|
| May 2024 | 24,905, the highest in the recent record |
| October 2025 | 2,917 |
| July 2026 | 4,317 |
From 24,905 acre feet to 2,917 in seventeen months, which is a loss of 88 percent . It has recovered to 4,317 and that is still less than a fifth of where it started.
There is no flow card because the gauge at the dam stopped. USGS site 10239000, Beaver River at Rocky Ford Dam, ended its record on 29 September 2003 . Twenty three years. There is a site further down at the town, but nothing continuous measures what this reservoir releases.
Where everything is
Eight places, three of which are dams that are not this dam.
Minersville Reservoir is managed by Beaver County, not by Utah State Parks. That was checked against the full state parks roster of forty six and this water is not on it.
Underwater spearfishing is not open here. Utah's rule lists forty two waters, lettered (a) to (pp), and Minersville is not among them . It is not on the guidebook's page 19 list either . No diving rule specific to this water was found in any source, which is an absence rather than a permission.
The standing gap between those two documents is confirmed again here: the rule lists forty two waters and the guidebook prints eight named waters plus a seventeen lake grouping, twenty five in all, while citing the same rule by number as its authority . Neither is preferred here and neither changes the answer for this reservoir.
One fish, and a rule three years out of date
The only species any agency names here is the one on a mercury advisory. The regulation everyone quotes was dropped from the guidebook, and it was never a slot limit.
Wiper
The only species any agency names in this reservoir, and the agency that names it is Utah's environmental quality department, in a mercury consumption advisory . An advisory takes tissue sampling, so it is about as hard as species evidence gets. Mercury 0.586, and only three waters in the state carry a wiper advisory at all.
The whole evidenced listThat is the entire list. One species, drawn once, because one species is all any agency names in this water.
The fishing guidebook regulates this reservoir twice and both rules are about "trout", without saying which trout . The water quality classification is 3A, cold water game fish, which is a use category and not an inventory . Neither of those is a species, so neither is drawn.
This is the shortest fish list in the series and it is not padded. A page that drew four plausible trout here would be making them up.
This water is known for an unusual regulation, and the version people repeat is the previous one.
| 2023 guidebook | 2026 guidebook |
|---|---|
| Limit 1 trout over 22 inches | Limit 1 trout over 22 inches |
| All trout 22 inches or smaller must be immediately released | All trout 22 inches or smaller must be immediately released |
| Artificial flies and lures only | Gone |
| An outlet channel closure | Gone |
The artificial flies and lures restriction is not in the current guidebook. That was confirmed five ways, including two separately issued questions phrased so that "no" was the easy answer .
Here is how the confusion gets manufactured. Three headings up the same guidebook page sits Mammoth Creek, whose rule reads "Limit 2 trout between 10 and 15 inches" and "All trout less than 10 inches or over 15 inches must be immediately released" . That is a real slot limit, on the same page, three entries away. It also carries the artificial flies and lures line that Minersville used to have.
This reservoir is widely called a Blue Ribbon fishery. This page cannot confirm it and will not deny it, and the reason is worth setting out because it has now blocked six pages in this series.
The wildlife division does not publish the list. Its Blue Ribbon page describes the programme, directs readers to a separate database to find a designated water, and prints neither a list nor a count .
41 waterbodies plus two mountain areas, in a funding release dated 15 July 2026 .
43 waterbodies plus two mountain areas, in another release .
44 waterbodies, with no mountain areas mentioned, in a third.
Three different numbers, and the units change too: some counts fold in mountain areas and some do not. Without dates on every release it cannot be told whether that is growth over time or inconsistency, and none of it names this reservoir.
The division does publish per water designation releases, and there is one for a neighbour. Gunlock Reservoir, in the next county south, has a release announcing its designation . No equivalent release naming Minersville was found, which is a not found rather than a no: if this water was designated before the division began publishing per water releases, there would be nothing to find.
Unresolved is the honest answer and it is better than a guess in either direction. The one lead worth following is that the division's own fishing application appends the words "(Blue Ribbon)" to a designated water's name, which means the designation exists as a queryable field somewhere. Find that endpoint and it resolves for every water in this series at once.
What to watch for
Nothing found in searchable press, a documented history of fish kills with no dates attached, and a high hazard dam whose condition has not been reassessed since 1991.
No incident of any kind at Minersville Reservoir was found in searchable press. No drowning, no missing person, no body recovery, no vehicle in the water, no boating fatality, no ice incident, no dive operation.
So a list assembled from search results would carry incidents from at least two states. The publishable sentence is "no incident found in searchable press", and it is not "nothing has happened here."
The one hazard statement about this water that comes from an agency is in the watershed plan, and it is a single clause :
"history of blue-green algal (phytoplankton) dominance and reported fish kills"
What this page will not do is turn that clause into a current warning. It is a watershed plan describing a documented history. Anyone planning to get into this water should check the state's current recreational monitoring before going, and should know that the plan describes a water with a bloom history.
And the water is often far lower than a map of it shows. The reservoir fell from 24,905 acre feet in May 2024 to 2,917 in October 2025 , which is a loss of about eighty eight percent. Shallow, warm, eutrophic water in a drawdown is the condition in which blooms happen, and the storage card above is the only public number that tracks it.
The dam inventory rates this structure High for hazard potential, which is a statement about what is downstream rather than about the dam's condition .
This page states both dates and draws no conclusion from the gap. An unredated assessment is a records problem, and a records problem is not a statement about a dam. The state file that would carry a current rating is closed to automated reading, and Utah rather than the federal government is the regulator here.
The structure is 1914 . It has no recorded modifications at all, which for a hundred and eleven year old high hazard dam is itself worth noticing, and which is a gap in the federal record rather than a finding about the dam.
Utah wrote down that this reservoir has a history of blue green algal dominance and reported fish kills, and gave no dates.
Fathom Restoration is a Utah 501(c)(3) that runs volunteer dive cleanups and is built to pull what does not belong out of Utah water, statewide.
Donate to Protect MinersvilleEvery figure on this page is quoted from the source named beside it.
Sources
How these were checked
Numbered sources are agencies. Lettered sources are everything else: two reproductions of Utah rules that the state's own rules site returns errors for, and the irrigation company that operates this reservoir. This page is unusual in the series for how much it does not say. No percentage of capacity, no surface area beyond the one federal polygon, no depth, no species list beyond a single fish, and no answer on Blue Ribbon. Each of those is an absence in the record rather than an absence of effort, and each is explained where it occurs. Where sources disagree, all of them are printed: that happens over the capacity, over which of two Utah advisory lists carries this water, and over how many Blue Ribbon waters the state has. One method note carried from earlier pages saved this one. A single read of the state advisory table found this reservoir and silently dropped the mercury figure from every row on the page. Asking directly returned it.National Inventory of Dams, federal identifier UT00259, filed under the name "Rocky Ford (Beaver)". Owner type Private, federally regulated dam No, regulator the Utah Division of Water Rights, year completed 1914, hazard potential High, condition assessment Satisfactory dated 1 January 1991, last inspected 21 June 2023, years modified empty, surface area field empty
National Inventory of Dams, every Utah dam whose name contains the string inersville. Two of them are debris dams several miles west and neither impounds this reservoir
National Hydrography Dataset, Minersville Reservoir, GNIS 01430378, published at 4.6076 square kilometres. This is the only surface area figure any agency publishes for this water
Geographic Names Information System. Minersville Reservoir is feature 1430378 and the town is feature 1430376, six miles west of the water. Three separate United States features are named Rocky Ford Reservoir
Minersville Reservoir storage, station 10238500:UT:BOR. It advertises daily, semimonthly and monthly reservoir contents and only the monthly series returns anything. The station actually named Rocky Ford on this network is a different station in Sevier County
Beaver River at Rocky Ford Dam, site 10239000. The gauge at the dam, and its record ends on 29 September 2003
Beaver River watershed total maximum daily load. Minersville Reservoir is impaired for total phosphorus, dissolved oxygen and temperature, is described as eutrophic and not supporting its designated class 3A use, and has a history of blue green algal dominance and reported fish kills
Utah fish consumption advisories. Minersville Reservoir, Beaver County, wiper, mercury 0.586, dated 4/23/18, with three separate meal limits. Four wiper rows appear across the whole page and they sit on three waterbodies
Game and fish advisories. Twelve Utah waters from a 2022 mercury analysis, and Minersville Reservoir is not among them
2026 Utah Fishing Guidebook, page 36. The Minersville Reservoir entry carries two bullets, and the name Rocky Ford appears nowhere in the document
2023 Utah Fishing Guidebook, page 34. The same water carried four bullets, including an artificial flies and lures restriction and an outlet channel closure that the current guidebook does not
Blue Ribbon fisheries programme allocates over 446 thousand dollars, 15 July 2026. States that 41 waterbodies plus two mountain areas hold the designation, and names four project waters, none of them Minersville
Blue Ribbon fisheries. The programme is described, readers are directed to a separate database to find a designated water, and no list and no count appear on the page
Point forecast for the reservoir. Forecast office Salt Lake City
Gunlock Reservoir designated a Blue Ribbon fishery. A per water designation release exists for Gunlock. No equivalent release naming Minersville Reservoir was found
Utah Administrative Code R317-2-13, classification of waters. The Beaver County table, in which Minersville Reservoir is classified 3A among others
Utah Administrative Code R657-13-9, underwater spearfishing. Forty two waters, running a to pp, and no Minersville
Rocky Ford Irrigation Company operating data. Gives 25,173 acre feet at the emergency spillway crest, elevation 5,505.0 feet, which is a figure no agency publishes
There is no percentage because there is no agreed capacity
Every other page in this series divides the current storage by a published capacity and prints a percentage. This one does not, and the reason is in a single federal record.
The national dam inventory holds two storage figures for this dam . Normal storage: 14,129 acre feet. Maximum storage: 38,733 acre feet. Neither states the elevation it corresponds to. They differ by a factor of 2.7.
The same reading would print as 11 percent against one of them and 31 percent against the other. A number that moves that far depending on an unstated choice is not information.
A third figure exists and it is not an agency figure. The irrigation company that operates the reservoir gives 25,173 acre feet at the emergency spillway crest, elevation 5,505.0 feet . It is the only one of the three that states its own datum, and it sits between the two federal numbers.
An observation, and not a resolution. The highest month in the gauge record is 24,905 acre feet in May 2024 , within one percent of the company's figure. That is consistent with 25,173 being the working full pool. It does not prove it, and no agency says so.
The storage reading itself comes from station 10238500:UT:BOR , which advertises daily, semimonthly and monthly and serves only monthly. The monthly series is also flagged derived rather than observed, and the card says so.