Capitol Lake
Capitol Lake in East Baton Rouge Parish County, Louisiana has a water quality grade of D (Nutrient-rich). Phosphorus: 310 µg/L.
- Type
- Hypereutrophic
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Capitol Lake →
Capitol Lake is a highly nutrient-loaded hypereutrophic lake in East Baton Rouge Parish County, Louisiana. Water quality is graded D based on 1 sampling years through 2024. Limited fish-species data available. Public access is available with 3 public boat landings.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-10-08. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyElevated nutrients
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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
No clarity data. Phosphorus level: 310 µg/L. Trophic State Index: 87.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 310 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 87 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Capitol Lake
Compare lakeside cabins, hotels, and vacation rentals near Capitol Lake in East Baton Rouge Parish County, Louisiana — 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 grade measures nutrients and algae, not lodging — cabins and rentals around Capitol Lake are listed below.
Top-rated places to stay near Capitol Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Recreation & Access
- City Park LakePublic
- Port Allen LockPublic
- South BoulevardPublic
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
Fishing Capitol Lake
EPA Impairment Status
Capitol Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit LA070503_00 · Official waterbody report
County Ranking
Ranked #1 of 1 lakes in East Baton Rouge Parish County
Nearby Lakes in East Baton Rouge Parish County
Frequently asked questions about Capitol Lake
Where is Capitol Lake?
- Capitol Lake is a lake in East Baton Rouge Parish County, Louisiana. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Capitol Lake?
- Capitol Lake in East Baton Rouge Parish County, Louisiana has a water quality grade of D (Nutrient-rich). Phosphorus: 310 µg/L.
Is Capitol Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Capitol Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
Are there boat ramps on Capitol Lake?
- Capitol Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include City Park Lake, Port Allen Lock, South Boulevard. Public access is listed as yes.
Explore Capitol Lake across LakeGrade
More Louisiana Lake Rankings
Other Grade D Lakes in Louisiana
Pointe Coupee Parish County · Nutrient-rich
Assumption Parish County · Nutrient-rich
Pointe Coupee Parish County · Nutrient-rich
Livingston Parish County · Nutrient-rich
St. Mary Parish County · Nutrient-rich
Terrebonne Parish County · Nutrient-rich
Hypereutrophic Lakes in Louisiana
Where this data comes from
37 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- LDEQ/Water Planning and Assessment (Louisiana)
LADEQWPD_WQX37 samples · 2020–2024
Analytical methods
- Total Phosphorus After Block Digestion
- 2130 B ~ Nephelometric Method
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
Named boat-access points from the USGS National Boat Ramps inventory