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LakeQuality

Castlenovo Lake

Warren County, Missouri10 acresView mapDirections

A
Excellent

Clarity, phosphorus, and algae all sit in the cleanest band for this region.

↑ up from B at the last regrade

Water temp
~78°F
Typical for Sep · EPA WQP
Clarity
6 ft
Secchi · sampled 2024
Level
No reading
No gauge
Trend
Declining
5 years of samples
  • Mesotrophic
  • #5 of 16 in the county

Castlenovo Lake in Warren County, Missouri has a water quality grade of A (Excellent). Water clarity: 6 ft visibility. Phosphorus: 16.8 µg/L. Chlorophyll-a (algae): 2.9 µg/L. Surface area: 10 acres.

Clarity
6 ft
Typical in September
78°F
Area
10 acres
Type
Mesotrophic
Trend
Declining
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Watch Castlenovo Lake’s letter

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Castlenovo Lake is a 10-acre mesotrophic lake in Warren County, Missouri. Water quality is graded A based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Compared to the 15 other monitored lakes in Warren County, Castlenovo Lake ranks #5 for water quality.

Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-09-21. Grade methodology: LakeQuality methodology.

Swimming Safety

Grade only

Low algae

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 A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

Compare the safest swimming lakes near St. Louis

Get alerts for Castlenovo Lake

Water Quality Grade: A (Excellent)

Murky, only visible to about 6 ft. Phosphorus 16.8 µg/L. Chlorophyll-a 2.9 µg/L. TSI 46. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)6 ftNot graded
Phosphorus16.8 µg/LGood
Chlorophyll-a (Algae)2.9 µg/LGood
Trophic State Index (TSI)46Mesotrophic

Moderate nutrients, good water quality

Water Temperature

Castlenovo Lake typically sits around 78°F at the surface in September. Summer average is about 83°F. Usually warmest in Jul (about 85°F) and coldest in Apr (about 64°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
64°
May
73°
Jun
81°
Jul
85°
Aug
82°
Sep
78°
Oct
Nov
Dec

Typical surface water temperature by month, from 102 field readings (20102024) via the EPA Water Quality Portal. See the full Castlenovo Lake water temperature breakdown →

Lake Details

CharacteristicValue
Surface Area10 acres

No bathymetric survey has been published for Castlenovo Lake, so its depth is not documented here.

Fishing Castlenovo Lake

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable+0.031 m/yr5
Phosphorus Declining+0.72 µg/L/yr5
Chlorophyll-a Declining+0.27 µg/L/yr5
See year-by-year chart →

Reservoir Info (USACE NID)

Castlenovo Lake is a man-made reservoir impounded by the Castelenovo Lake Dam (completed 1976), built primarily for recreation on the TR CHARRETTE CREEK; earth-type dam, 37 ft tall and 310 ft long.

Surface area
10 ac
Normal storage
109 ac-ft
Max storage
160 ac-ft
Drainage area
0.2 sq mi
Hazard class
High

Source: USACE National Inventory of Dams, NID ID MO30793 · Operator website · Matched by proximity (0.05 km)

County Ranking

Ranked #5 of 16 lakes in Warren County

Nearby Lakes in Warren County

Frequently asked questions about Castlenovo Lake

Where is Castlenovo Lake?

Castlenovo Lake is a lake in Warren County, Missouri. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Castlenovo Lake?

Castlenovo Lake in Warren County, Missouri has a water quality grade of A (Excellent). Water clarity: 6 ft visibility. Phosphorus: 16.8 µg/L. Chlorophyll-a (algae): 2.9 µg/L. Surface area: 10 acres.

Is Castlenovo Lake safe to swim in?

The A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

What is the water temperature of Castlenovo Lake?

Castlenovo Lake typically sits around 78°F at the surface in September, from 102 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.

Where this data comes from

113 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, ColumbiaUMC113 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)

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.