Raintree Lake
Cass County, Missouri475 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #4 of 4 in the county
- 37 ft max depth
Raintree Lake in Cass County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 2.5 ft visibility. Phosphorus: 66.4 µg/L. Chlorophyll-a (algae): 34.5 µg/L. Surface area: 475 acres.
- Clarity
- 2.5 ft
- Typical in September
- 77°F
- Max depth
- ~37 ft est.
- Area
- 475 acres
- Type
- Hypereutrophic
- Phosphorus
- 66.4 µg/L
- Chlorophyll-a
- 34.5 µg/L
- Trend
- ↑ Improving
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Stays near Raintree Lake
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Watch Raintree Lake’s letter
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Raintree Lake is a 475-acre highly nutrient-loaded hypereutrophic lake in Cass County, Missouri with an estimated average depth of about 37 feet. Water quality is graded F based on 2 sampling years through 2023. Overall water quality is improving over recent sampling years. Compared to the 3 other monitored lakes in Cass County, Raintree Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2023-09-17. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyAlgae risk
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The F is nutrients and algae, not a swimming clearance. Raintree Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.5 ft of visibility. Phosphorus 66.4 µg/L. Chlorophyll-a 34.5 µg/L. TSI 65. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 66.4 µg/L | Poor |
| Chlorophyll-a (Algae) | 34.5 µg/L | Poor |
| Trophic State Index (TSI) | 65 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Raintree Lake typically sits around 77°F at the surface in September. Summer average is about 83°F. Usually warmest in Jul (about 86°F) and coldest in May (about 71°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 56 field readings (2010–2023) via the EPA Water Quality Portal. See the full Raintree Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~37 ft est. |
| Average Depth | ~11 ft est. |
| Surface Area | 475 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Missouri has not published bathymetry for Raintree Lake.
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.
Fishing Raintree Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.129 m/yr | 4 |
| Phosphorus | ↑ Improving | -3.76 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -9.89 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Raintree Lake is a man-made reservoir impounded by the Raintree Lake Dam (completed 1974), built primarily for recreation on the MIDDLE BIG CREEK; earth-type dam, 55 ft tall and 1,900 ft long.
- Surface area
- 475 ac
- Normal storage
- 3,570 ac-ft
- Max storage
- 7,220 ac-ft
- Drainage area
- 7.45 sq mi
- Hazard class
- High
- Owner
- RAINTREE LAKE DEV CORP
Source: USACE National Inventory of Dams, NID ID MO20388 · Operator website
EPA Impairment Status
Raintree Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7213.00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Raintree Lake under Clean Water Act (NPDES) discharge permits.
- Redford Construction WwtfPleasant Hill · 2.1 mi away · NPDES MO0135488
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.
County Ranking
Ranked #4 of 4 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Raintree Lake
Where is Raintree Lake?
- Raintree Lake is a lake in Cass County, Missouri. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Raintree Lake?
- Raintree Lake in Cass County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 2.5 ft visibility. Phosphorus: 66.4 µg/L. Chlorophyll-a (algae): 34.5 µg/L. Surface area: 475 acres.
Is Raintree Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Raintree Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
What is the water temperature of Raintree Lake?
- Raintree Lake typically sits around 77°F at the surface in September, from 56 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Raintree Lake?
- No published bathymetric survey covers Raintree Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 37 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 475 acres.
Explore Raintree Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Missouri's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
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Where this data comes from
61 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC61 samples · 2020–2023
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)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)