Chatfield Reservoir
Jefferson County, Colorado1,150 acresView mapDirections
Colorado WQCD publishes the water-quality measurements for Chatfield Reservoir. Here is what has been measured.
- Eutrophic
- Impaired · Metals (other than mercury)
- 64 ft max depth
- Public access
- Limited data
Chatfield Reservoir in Jefferson County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 27 µg/L. Surface area: 1150 acres.
Chatfield Reservoir is a 1,150-acre productive, nutrient-rich eutrophic lake in Jefferson County, Colorado with an estimated average depth of about 64 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 2020-08-21. Methodology: how these readings are compared.
Chatfield Reservoir covers about 1,200 acres in Jefferson County. It has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. Vrbo is where to look for cabins and lake homes around Chatfield Reservoir, and Booking.com and Expedia search hotels near the lake for your dates.
What Chatfield Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
- Big water1,150 acres
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Chatfield Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury). Check local advisories before you swim.
Whether Chatfield 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 Chatfield Reservoir
These are the measurements Colorado WQCD publishes for Chatfield Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 6.2 ft. Phosphorus 27 µg/L. TSI 51.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 27µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading 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. | 51 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Chatfield Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~64 ft est.
Surface area
1,150 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 Chatfield Reservoir.
Lake Size & Watershed
Watershed (drainage) area
3,032 sq mi
HydroLAKES / HydroSHEDS
Shoreline
8.2 mi
HydroLAKES / HydroSHEDS
Elevation
5,440 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
- Chatfield State ParkPublic
- Chatfield State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Chatfield Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Chatfield Reservoir in Jefferson County, Colorado — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Chatfield Reservoir
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Fishing Chatfield Reservoir
Reservoir Info (USACE NID)
Chatfield Reservoir is a man-made reservoir impounded by the Chatfield Dam (completed 1973), built primarily for flood risk reduction on the South Platte River; earth-type dam, 148 ft tall and 13,136 ft long.
- Surface area
- 1,150 ac
- Normal storage
- 20,000 ac-ft
- Max storage
- 355,000 ac-ft
- Drainage area
- 3,018 sq mi
- Hazard class
- High
- Owner
- USACE - Omaha District
All listed purposes: Flood Risk Reduction;Irrigation;Recreation.
Source: USACE National Inventory of Dams, NID ID CO01281 · Operator website
EPA Impairment Status
Chatfield 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.
Source: EPA ATTAINS assessment unit COSPUS06b_A · Official waterbody report
Nearby Lakes in Jefferson County
Frequently asked questions about Chatfield Reservoir
Where is Chatfield Reservoir?
- Chatfield Reservoir is a lake in Jefferson County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.
What is the water quality of Chatfield Reservoir?
- Chatfield Reservoir in Jefferson County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 27 µg/L. Surface area: 1150 acres.
Is Chatfield Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Chatfield Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury). Check local advisories before you swim.
How deep is Chatfield Reservoir?
- No published bathymetric survey covers Chatfield Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 64 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 1150 acres.
Are there boat ramps on Chatfield Reservoir?
- Chatfield Reservoir has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Chatfield State Park, Chatfield State Park. Public access is listed as yes.
Can I fish at Chatfield Reservoir?
- Chatfield Reservoir has 2 documented boat landings 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.
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Where this data comes from
9 measurements from 2 monitoring stations, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Colorado Dept. of Public Health & Environment-WQCD
21COL001_WQX9 samples · 2020
Analytical methods
- Secchi disk depth measurement
- Phosphorus by Colorimetry
- Nitrogen in Water by Pyrolysis Detection
Monitoring station identifiers (2)
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