Spanish Lake
St. Louis County, MissouriView mapDirections
Missouri DNR publishes the water-quality measurements for Spanish Lake. Here is what has been measured.
- Hypereutrophic
- 40 ft max depth
- Public access
Spanish Lake in St. Louis County, Missouri has water-quality measurements published by Missouri DNR, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 347.8 µg/L. Chlorophyll-a (algae): 62.6 µg/L.
Spanish Lake is a highly nutrient-loaded hypereutrophic lake in St. Louis County, Missouri with an estimated average depth of about 40 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 4 other monitored lakes in St. Louis County, Spanish Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-09-21. Methodology: how these readings are compared.
Spanish Lake has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Spanish Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Spanish Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyAlgae risk
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. Check local advisories before you swim.
Whether Spanish Lake is safe to swim in today is a call for the Missouri Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Spanish Lake
These are the measurements Missouri DNR publishes for Spanish Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1.6 ft of visibility. Phosphorus 347.8 µg/L. Chlorophyll-a 62.6 µg/L. TSI 77.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 348µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 62.6µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 77 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Spanish Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Spanish Lake typically sits around 77°F at the surface in September. Summer average is about 84°F. Usually warmest in Jul (about 85°F) and coldest in Apr (about 65°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (65°F) to its warmest (85°F).
Typical surface water temperature by month, from 38 field readings (2020–2024) via the EPA Water Quality Portal. See the full Spanish Lake water temperature breakdown →
Lake Details
Max depth
~40 ft est.
Public access
Yes
Listed by Missouri DNR
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Missouri has not published bathymetry for Spanish Lake.
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Surface area
32 acres
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
502 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
- Spanish LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Spanish Lake
Compare lakeside cabins, hotels, and vacation rentals near Spanish Lake in St. Louis County, Missouri — 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Spanish Lake are listed below.
Top-rated places to stay near Spanish Lake
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Missouri’s top lakes →
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Fishing Spanish Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2020–2024).
Water clarity
Worsening5 years
Phosphorus
Worsening+16.19 µg/L/yr5 years
Chlorophyll-a
Worsening+14.35 µg/L/yr5 years
Regulated Pollution Sources Nearby
5 EPA-permitted facilities operate within about 5 miles of Spanish Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 3 facilities have a reported Clean Water Act violation in the past three years.
- Msd Coldwater Creek WwtpFlorissant · 3.4 mi away · NPDES MO0025160MajorRecent violation
- St Louis, Chain Rocks WtpSt. Louis · 3.5 mi away · NPDES MO0000604Recent violation
- Spire Missouri Inc.St. Louis · 4.9 mi away · NPDES MO0114804Recent violation
- Maintenance Bldg City Of Black JackBlack Jack · 3.1 mi away · NPDES MONX00333
- Chain Of Rocks RdfGranite City · 4.8 mi away · NPDES IL0075523
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in St. Louis County
Frequently asked questions about Spanish Lake
Where is Spanish Lake?
- Spanish Lake is a lake in St. Louis County, Missouri. Its water-quality measurements are published by Missouri DNR and shown on this page as reported.
What is the water quality of Spanish Lake?
- Spanish Lake in St. Louis County, Missouri has water-quality measurements published by Missouri DNR, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 347.8 µg/L. Chlorophyll-a (algae): 62.6 µg/L.
Is Spanish Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Spanish Lake?
- Spanish Lake typically sits around 77°F at the surface in September, from 38 EPA Water Quality Portal field readings (2020–2024). That is a typical value for the month, not a live reading.
How deep is Spanish Lake?
- No published bathymetric survey covers Spanish Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 40 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Spanish Lake?
- Spanish Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Spanish Lake. Public access is listed as yes.
Can I fish at Spanish Lake?
- Spanish Lake 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 Missouri's fish and wildlife agency, so check its current regulations before you go.
Explore Spanish Lake across LakeQuality
Planning a trip around Gateway Arch?
Spanish Lake is about 12 miles from Gateway Arch National Park. 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 Gateway Arch →More lakes in Missouri
Other Lakes in Missouri
Hypereutrophic Lakes in Missouri
Where this data comes from
114 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC114 samples · 2020–2024
Analytical methods
- Depth, Secchi disk in meters
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory