Rifle Gap Reservoir
Garfield County, Colorado435 acresView mapDirections
Colorado WQCD publishes the water-quality measurements for Rifle Gap Reservoir. Here is what has been measured.
- Impaired · Mercury
- 17 ft max depth
- Public access
- Limited data
Rifle Gap Reservoir in Garfield County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 7.9 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 0.5 µg/L. Surface area: 435 acres.
Rifle Gap Reservoir is a 435-acre lake in Garfield County, Colorado with an estimated average depth of about 17 feet. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, CDPHE, last sampled 2023-05-09. Methodology: how these readings are compared.
What Rifle Gap Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Rifle Gap Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury). Check local advisories before you swim.
Whether Rifle Gap Reservoir is safe to swim in today is a call for the Water Quality Control Division of the Colorado Department of Public Health and Environment and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rifle Gap Reservoir
These are the measurements Colorado WQCD publishes for Rifle Gap Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 7.9 ft. Phosphorus 10 µg/L. Chlorophyll-a 0.5 µg/L. TSI 36.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 0.5µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 36 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Rifle Gap Reservoir
Answers come straight from the public measurements and survey records on this page.
→ Rifle Gap Reservoir water level: the live USGS gauge reading
Lake Details
Max depth
~17 ft est.
Surface area
435 acres
Public access
Yes
Listed by Colorado WQCD
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Colorado has not published bathymetry for Rifle Gap Reservoir.
Lake Size & Watershed
Watershed (drainage) area
139 sq mi
HydroLAKES / HydroSHEDS
Shoreline
4.3 mi
HydroLAKES / HydroSHEDS
Elevation
5,974 ft
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
- Rifle Gap State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
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Fishing Rifle Gap Reservoir
Reservoir Info (USACE NID)
Rifle Gap Reservoir is a man-made reservoir impounded by the Rifle Gap Dam (completed 1967), built primarily for irrigation on the Rifle Creek; earth-type dam, 157 ft tall and 1,450 ft long.
- Surface area
- 435 ac
- Normal storage
- 12,168 ac-ft
- Max storage
- 18,261 ac-ft
- Drainage area
- 136.52 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Irrigation;Recreation.
Source: USACE National Inventory of Dams, NID ID CO01692 · Operator website
EPA Impairment Status
Rifle Gap Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Drinking water, Aquatic life.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit COLCLC20_B · Official waterbody report
Nearby Lakes in Garfield County
Frequently asked questions about Rifle Gap Reservoir
Where is Rifle Gap Reservoir?
- Rifle Gap Reservoir is a lake in Garfield County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.
What is the water quality of Rifle Gap Reservoir?
- Rifle Gap Reservoir in Garfield County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 7.9 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 0.5 µg/L. Surface area: 435 acres.
Is Rifle Gap Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Rifle Gap Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury). Check local advisories before you swim.
How deep is Rifle Gap Reservoir?
- No published bathymetric survey covers Rifle Gap Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 17 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 435 acres.
Are there boat ramps on Rifle Gap Reservoir?
- Rifle Gap Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Rifle Gap State Park. Public access is listed as yes.
Can I fish at Rifle Gap Reservoir?
- Rifle Gap Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Colorado's fish and wildlife agency, so check its current regulations before you go.
Explore Rifle Gap Reservoir across LakeQuality
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Where this data comes from
12 measurements from 4 monitoring stations, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Colorado Dept. of Public Health & Environment-WQCD
21COL001_WQX12 samples · 2022–2023
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 (4)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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