Standley Lake
Jefferson County, Colorado1,222 acresView mapDirections
Colorado WQCD publishes the water-quality measurements for Standley Lake. Here is what has been measured.
- 95 ft max depth
- Limited data
Standley Lake in Jefferson County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 20.5 ft visibility. Surface area: 1222 acres.
Standley Lake is a 1,222-acre lake in Jefferson County, Colorado with an estimated average depth of about 95 feet.
Source: EPA Water Quality Portal sampling records, CDPHE, last sampled 2025-07-28. Methodology: how these readings are compared.
Standley Lake covers about 1,200 acres in Jefferson County. For a place on the water, look through cabin and lake-house rentals near Standley Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Standley Lake is good for
From access and monitoring records, not editorial picks.
- Clear water20.5 ft of visibility
- Big water1,222 acres
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Standley Lake 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 Standley Lake
These are the measurements Colorado WQCD publishes for Standley Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 20.5 ft down. TSI 34.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 20.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| 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. | 34 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Standley Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~95 ft est.
Surface area
1,222 acres
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Colorado has not published bathymetry for Standley Lake.
Lake Size & Watershed
Watershed (drainage) area
16 sq mi
HydroLAKES / HydroSHEDS
Shoreline
7.3 mi
HydroLAKES / HydroSHEDS
Elevation
5,512 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.
Stays via Stay22
Stays near Standley Lake
Compare lakeside cabins, hotels, and vacation rentals near Standley Lake 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 Standley Lake
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Fishing Standley Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Reservoir Info (USACE NID)
Standley Lake is a man-made reservoir impounded by the Standley Lake (completed 1913), built primarily for irrigation on the Big Dry Creek; earth-type dam, 123 ft tall and 5,900 ft long.
- Surface area
- 1,222 ac
- Normal storage
- 43,344 ac-ft
- Max storage
- 54,740 ac-ft
- Drainage area
- 15 sq mi
- Hazard class
- High
- Owner
- FARMERS RESERVOIR AND IRRIGATION COMPANY (EDGAR, S
All listed purposes: Irrigation;Water Supply.
Source: USACE National Inventory of Dams, NID ID CO00101 · Operator website
Nearby Lakes in Jefferson County
Frequently asked questions about Standley Lake
Where is Standley Lake?
- Standley Lake 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 Standley Lake?
- Standley Lake in Jefferson County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Water clarity: 20.5 ft visibility. Surface area: 1222 acres.
Is Standley Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Standley Lake?
- No published bathymetric survey covers Standley Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 95 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 1222 acres.
Explore Standley Lake across LakeQuality
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Where this data comes from
36 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS36 samples · 2020–2025
Monitoring station identifiers (1)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)