Mountain Home Reservoir
Costilla County, Colorado597 acresView mapDirections
Not enough samples to grade — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). No letter yet. Here is what we do have.
- 63 ft max depth
- Public access
- Limited data
Mountain Home Reservoir in Costilla County, Colorado is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.4 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 6.2 µg/L. Surface area: 597 acres.
- Clarity
- 14.4 ft
- Max depth
- ~63 ft est.
- Area
- 597 acres
- Public access
- Yes
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Watch Mountain Home Reservoir’s letter
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Why Mountain Home Reservoir has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mountain Home Reservoir, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by CDPHE and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Mountain Home Reservoir is a 597-acre lake in Costilla County, Colorado with an estimated average depth of about 63 feet. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, CDPHE, last sampled 2020-07-27. Grade methodology: LakeQuality methodology.
What Mountain Home Reservoir is good for
From access and monitoring records, not editorial picks.
- Clear water14.4 ft of visibility
- Boat launch2 documented ramps
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Mountain Home Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury), oxygen depletion (low DO). Check local advisories before you swim.
Water quality measurements for Mountain Home Reservoir
These readings exist but are not enough for an A–F grade — see why.
Good clarity, visible to about 14.4 ft. Phosphorus 17 µg/L. Chlorophyll-a 6.2 µg/L. TSI 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.4 ft | Not graded |
| Phosphorus | 17 µg/L | Not graded |
| Chlorophyll-a (Algae) | 6.2 µg/L | Not graded |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~63 ft est. |
| Surface Area | 597 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Colorado has not published bathymetry for Mountain Home Reservoir.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Mountain Home Reservoir State Wildlife AreaPublic
- Mountain Home Reservoir State Wildlife AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Mountain Home Reservoir
Reservoir Info (USACE NID)
Mountain Home Reservoir is a man-made reservoir impounded by the Mountain Home (completed 1908), built primarily for irrigation on the Trinchera Creek; earth-type dam, 153 ft tall and 490 ft long.
- Surface area
- 597 ac
- Normal storage
- 17,964 ac-ft
- Max storage
- 26,230 ac-ft
- Drainage area
- 70 sq mi
- Hazard class
- High
- Owner
- TRACY KESTER,
All listed purposes: Irrigation;Fish and Wildlife Pond;Recreation.
Source: USACE National Inventory of Dams, NID ID CO00818 · Operator website
EPA Impairment Status
Mountain Home Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit CORGRG38_E · Official waterbody report
Graded lakes near Mountain Home Reservoir
Mountain Home Reservoir has no grade, but these lakes within a short drive do.
Nearby Lakes in Costilla County
Frequently asked questions about Mountain Home Reservoir
Where is Mountain Home Reservoir?
- Mountain Home Reservoir is a lake in Costilla County, Colorado. LakeQuality has not rated this lake (UNRATED) — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
What is the water quality grade for Mountain Home Reservoir?
- Mountain Home Reservoir in Costilla County, Colorado is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.4 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 6.2 µg/L. Surface area: 597 acres.
Is Mountain Home Reservoir safe to swim in?
- The letter is not a swimming clearance. Mountain Home Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury), oxygen depletion (low DO). Check local advisories before you swim.
How deep is Mountain Home Reservoir?
- No published bathymetric survey covers Mountain Home Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 63 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 597 acres.
Are there boat ramps on Mountain Home Reservoir?
- Mountain Home Reservoir has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mountain Home Reservoir State Wildlife Area, Mountain Home Reservoir State Wildlife Area. Public access is listed as yes.
Explore Mountain Home Reservoir across LakeQuality
17.9 mi away · 30 ft
22.9 mi away · recorded at 68°F
Species activity outlook by water temperature and season
Where to stay at Colorado's top lakes, each with its grade
Colorado's cleanest and most-polluted lakes, ranked
Planning a trip around Great Sand Dunes?
Mountain Home Reservoir is about 30 miles from Great Sand Dunes National Park & Preserve. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Great Sand Dunes →More Colorado Lake Rankings
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Where this data comes from
4 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Colorado Dept. of Public Health & Environment-WQCD
21COL001_WQX4 samples · 2020
Analytical methods
- Secchi disk depth measurement
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Nitrogen in Water by Pyrolysis Detection
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory