Lake O the Pines Mid Lake
Marion County, Texas18,700 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- Impaired · pH / acidity
- #1 of 4 in the county
- Public access
Lake O the Pines Mid Lake in Marion County, Texas has a water quality grade of F (Algae-prone). Water clarity: 2.7 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 41.7 µg/L. Surface area: 18700 acres.
- Clarity
- 2.7 ft
- Area
- 18,700 acres
- Type
- Hypereutrophic
- Phosphorus
- 30 µg/L
- Chlorophyll-a
- 41.7 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
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Stays near Lake O the Pines Mid Lake
Compare lakeside cabins, hotels, and vacation rentals near Lake O the Pines Mid Lake in Marion 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Lake O the Pines Mid Lake are listed below.
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Lake O the Pines Mid Lake is a 18,700-acre highly nutrient-loaded hypereutrophic lake in Marion County, Texas. Water quality is graded F 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 13 public boat landings. Compared to the 3 other monitored lakes in Marion County, Lake O the Pines Mid Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2025-09-16. Grade methodology: LakeQuality methodology.
What Lake O the Pines Mid Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch13 documented ramps
- Big water18,700 acres
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. Lake O the Pines Mid Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.7 ft of visibility. Phosphorus 30 µg/L. Chlorophyll-a 41.7 µg/L. TSI 61. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.7 ft | Not graded |
| Phosphorus | 30 µg/L | Good |
| Chlorophyll-a (Algae) | 41.7 µg/L | Poor |
| Trophic State Index (TSI) | 61 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Current Conditions
USGS snapshot Sep 7, 2026, 3:30 PM from gauge 07345900 (Lk O' the Pines nr Jefferson, TX). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
→ Lake O the Pines Mid Lake water level: the live USGS gauge reading
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 18,700 acres |
| Public Access | Yes |
No bathymetric survey has been published for Lake O the Pines Mid Lake, so its depth is not documented here.
Recreation & Access
- FM 3001 BridgePublic
- Lake O' The Pines DamPublic
- Brushy Creek ParkPublic
- Hurricane Creek Recreation AreaPublic
- Lakeside (Pine Harbor)Public
- Holiday HarborPublic
Showing 6 of 13 documented landings from the USGS National Boat Ramps inventory.
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake O the Pines Mid Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.027 m/yr | 6 |
| Phosphorus | ↓ Declining | +2.75 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +5.92 µg/L/yr | 6 |
Reservoir Info (USACE NID)
Lake O the Pines Mid Lake is a man-made reservoir impounded by the Ferrells Bridge Dam (completed 1958), built primarily for flood risk reduction on the Cypress Creek; earth-type dam, 97 ft tall and 10,600 ft long.
- Surface area
- 18,700 ac
- Normal storage
- 254,900 ac-ft
- Max storage
- 1,998,740 ac-ft
- Drainage area
- 850 sq mi
- Hazard class
- High
- Owner
- USACE - Fort Worth District
All listed purposes: Flood Risk Reduction;Fish and Wildlife Pond;Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID TX00020 · Operator website · Matched by proximity (0.91 km)
EPA Impairment Status
Lake O the Pines 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-0403_01 · Official waterbody report · Matched by proximity (2.77 km)
County Ranking
Ranked #1 of 4 lakes in Marion County
Nearby Lakes in Marion County
Frequently asked questions about Lake O the Pines Mid Lake
Where is Lake O the Pines Mid Lake?
- Lake O the Pines Mid Lake is a lake in Marion County, Texas. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake O the Pines Mid Lake?
- Lake O the Pines Mid Lake in Marion County, Texas has a water quality grade of F (Algae-prone). Water clarity: 2.7 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 41.7 µg/L. Surface area: 18700 acres.
Is Lake O the Pines Mid Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Lake O the Pines Mid Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
What is the water level at Lake O the Pines Mid Lake?
- The USGS snapshot on this page for Lake O the Pines Mid Lake is 228.03 ft of water-surface elevation, recorded Sep 7, 2026, 3:30 PM at gauge 07345900. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
Are there boat ramps on Lake O the Pines Mid Lake?
- Lake O the Pines Mid Lake has 13 documented boat landings in the USGS National Boat Ramps inventory. Named access points include FM 3001 Bridge, Lake O' The Pines Dam, Brushy Creek Park, Hurricane Creek Recreation Area, among others. Public access is listed as yes.
Explore Lake O the Pines Mid Lake across LakeQuality
More Texas Lake Rankings
Other Grade F Lakes in Texas
Hypereutrophic Lakes in Texas
Where this data comes from
66 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
TCEQMAIN66 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
Named boat-access points from the USGS National Boat Ramps inventory