Lake Sweetwater Mid Lake
Nolan County, Texas588 acresView mapDirections
Clarity, phosphorus, and algae sit in the clean band for this region.
↑ up from C at the last regrade
- Eutrophic
- Impaired · Salinity / chlorides
- #1 of 1 in the county
- 15 ft max depth
- Public access
- Limited data
Lake Sweetwater Mid Lake in Nolan County, Texas has a water quality grade of B (Good). Water clarity: 3.6 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 588 acres.
- Clarity
- 3.6 ft
- Max depth
- ~15 ft est.
- Area
- 588 acres
- Type
- Eutrophic
- Phosphorus
- 30 µg/L
- Chlorophyll-a
- 8.3 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
Stays via Stay22
Stays near Lake Sweetwater Mid Lake
Compare lakeside cabins, hotels, and vacation rentals near Lake Sweetwater Mid Lake in Nolan County, Texas — 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.
Top-rated places to stay near Lake Sweetwater Mid Lake
Prices for Sep 11–13, 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 Texas’s top lakes →
Watch Lake Sweetwater Mid Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Lake Sweetwater Mid Lake is a 588-acre productive, nutrient-rich eutrophic lake in Nolan County, Texas with an estimated average depth of about 15 feet. Water quality is graded B based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2025-08-11. Grade methodology: LakeQuality methodology.
What Lake Sweetwater Mid Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming Safety
Grade onlyLimited data
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 B is nutrients and algae, not a swimming clearance. Lake Sweetwater Mid Lake is listed impaired under Clean Water Act §303(d) (IR 5) for salinity / chlorides. Check local advisories before you swim.
Water Quality Grade: B (Good)
Murky, only visible to about 3.6 ft. Phosphorus 30 µg/L. Chlorophyll-a 8.3 µg/L. TSI 54. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.6 ft | Not graded |
| Phosphorus | 30 µg/L | Good |
| Chlorophyll-a (Algae) | 8.3 µg/L | Good |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~15 ft est. |
| Average Depth | ~9 ft est. |
| Surface Area | 588 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Texas has not published bathymetry for Lake Sweetwater Mid 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.
Recreation & Access
- Lake SweetwaterPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake Sweetwater Mid Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.226 m/yr | 5 |
| Phosphorus | ↓ Declining | +10 µg/L/yr | 3 |
| Chlorophyll-a | ↓ Declining | +6.16 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Lake Sweetwater Mid Lake is a man-made reservoir impounded by the Lake Sweetwater Dam (completed 1930), built primarily for water supply on the Bitter & Cottonwood Creeks; earth-type dam, 58 ft tall and 3,030 ft long.
- Surface area
- 588 ac
- Normal storage
- 10,975 ac-ft
- Max storage
- 19,340 ac-ft
- Drainage area
- 104 sq mi
- Hazard class
- High
- Owner
- CITY OF SWEETWATER
All listed purposes: Water Supply;Recreation.
Source: USACE National Inventory of Dams, NID ID TX02735 · Operator website · Matched by proximity (0.49 km)
EPA Impairment Status
Lake Sweetwater Mid Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit TX-1237_01 · Official waterbody report · Matched by proximity (1.41 km)
County Ranking
Ranked #1 of 1 lakes in Nolan County
Nearby Lakes in Nolan County
Frequently asked questions about Lake Sweetwater Mid Lake
Where is Lake Sweetwater Mid Lake?
- Lake Sweetwater Mid Lake is a lake in Nolan County, Texas. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Sweetwater Mid Lake?
- Lake Sweetwater Mid Lake in Nolan County, Texas has a water quality grade of B (Good). Water clarity: 3.6 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 588 acres.
Is Lake Sweetwater Mid Lake safe to swim in?
- The B is nutrients and algae, not a swimming clearance. Lake Sweetwater Mid Lake is listed impaired under Clean Water Act §303(d) (IR 5) for salinity / chlorides. Check local advisories before you swim.
How deep is Lake Sweetwater Mid Lake?
- No published bathymetric survey covers Lake Sweetwater Mid Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 15 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 588 acres.
Are there boat ramps on Lake Sweetwater Mid Lake?
- Lake Sweetwater Mid Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Sweetwater. Public access is listed as yes.
Explore Lake Sweetwater Mid Lake across LakeQuality
More Texas Lake Rankings
Other Grade B Lakes in Texas
Eutrophic Lakes in Texas
Where this data comes from
47 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Texas Commission on Environmental Quality
TCEQMAIN47 samples · 2020–2025
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory