Dems Lake
Sumter County, Alabama10,000 acresView mapDirections
ADEM publishes the water-quality measurements for Dems Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
- Public access
Dems Lake in Sumter County, Alabama has water-quality measurements published by ADEM, shown here as reported. Water clarity: 2.7 ft visibility. Phosphorus: 24 µg/L. Chlorophyll-a (algae): 14.2 µg/L. Surface area: 10000 acres.
Dems Lake is a 10,000-acre productive, nutrient-rich eutrophic lake in Sumter County, Alabama. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 4 public boat landings. Compared to the 1 other monitored lakes in Sumter County, Dems Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, ADEM, last sampled 2025-10-27. Methodology: how these readings are compared.
What Dems Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch4 documented ramps
- Camping1 public campground nearby
- Big water10,000 acres
Swimming conditions
Readings onlyModerate algae
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. Dems Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Dems Lake is safe to swim in today is a call for the Alabama Department of Environmental Management and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Dems Lake
These are the measurements ADEM publishes for Dems 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 2.7 ft of visibility. Phosphorus 24 µg/L. Chlorophyll-a 14.2 µg/L. TSI 56.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 24µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 14.2µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 56 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Dems Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
10,000 acres
Public access
Yes
Listed by ADEM
No bathymetric survey has been published for Dems Lake, so its depth is not documented here.
Recreation & Access
- BelmontPublic
- Foscue CreekPublic
- Demopolis City LandingPublic
- Lock No. 4Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Dems Lake
- Foscue Creek0.7 kmReserve
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Stays via Stay22
Stays near Dems Lake
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Top-rated places to stay near Dems Lake
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Fishing Dems Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2014–2025).
Water clarity
Worsening5 years
Phosphorus
Worsening+0.8 µg/L/yr5 years
Chlorophyll-a
Worsening+0.45 µg/L/yr5 years
Reservoir Info (USACE NID)
Dems Lake is a man-made reservoir impounded by the Demopolis Lock and Dam (completed 1955), built primarily for navigation on the Tombigbee River; gravity-type dam, 63 ft tall and 1,770 ft long.
- Surface area
- 10,000 ac
- Normal storage
- 120,000 ac-ft
- Max storage
- 150,000 ac-ft
- Drainage area
- 15,385 sq mi
- Hazard class
- Significant
- Owner
- USACE - Mobile District
All listed purposes: Navigation;Recreation.
Source: USACE National Inventory of Dams, NID ID AL01430 · Operator website · Matched by proximity (0.41 km)
EPA Impairment Status
Dems Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit AL03160201-0401-102 · Official waterbody report
Nearby Lakes in Sumter County
Frequently asked questions about Dems Lake
Where is Dems Lake?
- Dems Lake is a lake in Sumter County, Alabama. Its water-quality measurements are published by ADEM and shown on this page as reported.
What is the water quality of Dems Lake?
- Dems Lake in Sumter County, Alabama has water-quality measurements published by ADEM, shown here as reported. Water clarity: 2.7 ft visibility. Phosphorus: 24 µg/L. Chlorophyll-a (algae): 14.2 µg/L. Surface area: 10000 acres.
Is Dems Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Dems Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Are there boat ramps on Dems Lake?
- Dems Lake has 4 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Belmont, Foscue Creek, Demopolis City Landing, Lock No. 4. Public access is listed as yes.
Can I fish at Dems Lake?
- Dems Lake has 4 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Alabama's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Dems Lake?
- Dems Lake has 1 public campground from USGS The National Map within 5 km, including Foscue Creek. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
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Where this data comes from
129 measurements from 1 monitoring station, 2014–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- ALABAMA DEPT. OF ENVIRONMENTAL MANAGEMENT - WATER QUALITY DATA
21AWIC129 samples · 2014–2025
Analytical methods
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2120 B ~ Color in Water by Visual Comparison
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
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory
Public campgrounds from USGS The National Map Structures, within about 3 miles