Walter E Long Lake Mid Lake
Travis County, Texas1,269 acresView mapDirections
TCEQ publishes the water-quality measurements for Walter E Long Lake Mid Lake. Here is what has been measured.
- Eutrophic
- Limited data
Walter E Long Lake Mid Lake in Travis County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 3.6 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 15.7 µg/L. Surface area: 1269 acres.
Walter E Long Lake Mid Lake is a 1,269-acre productive, nutrient-rich eutrophic lake in Travis County, Texas. Overall water quality is improving over recent sampling years. Compared to the 2 other monitored lakes in Travis County, Walter E Long Lake Mid Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled 2024-07-31. Methodology: how these readings are compared.
What Walter E Long Lake Mid Lake is good for
From access and monitoring records, not editorial picks.
- Big water1,269 acres
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Walter E Long Lake Mid Lake is safe to swim in today is a call for the Texas Commission on Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Walter E Long Lake Mid Lake
These are the measurements TCEQ publishes for Walter E Long Lake Mid Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.6 ft. Phosphorus 30 µg/L. Chlorophyll-a 15.7 µg/L. TSI 57.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 30µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 15.7µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 57 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Walter E Long Lake Mid Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
1,269 acres
No bathymetric survey has been published for Walter E Long Lake Mid Lake, so its depth is not documented here.
Stays via Stay22
Stays near Walter E Long Lake Mid Lake
Compare lakeside cabins, hotels, and vacation rentals near Walter E Long Lake Mid Lake in Travis 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Walter E Long Lake Mid Lake are listed below.
Top-rated places to stay near Walter E Long Lake Mid Lake
Prices for Oct 30–Nov 1, 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 →
Follow Walter E Long Lake Mid Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Walter E Long Lake Mid Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2021–2024).
Water clarity
Worsening4 years
Phosphorus
Improving-6.43 µg/L/yr3 years
Chlorophyll-a
Improving-3.36 µg/L/yr4 years
Reservoir Info (USACE NID)
Walter E Long Lake Mid Lake is a man-made reservoir impounded by the Decker Creek Dam (completed 1967), built primarily for recreation on the Decker Creek; earth-type dam, 75 ft tall and 6,390 ft long.
- Surface area
- 1,269 ac
- Normal storage
- 33,940 ac-ft
- Max storage
- 45,200 ac-ft
- Drainage area
- 9.3 sq mi
- Hazard class
- High
- Owner
- CITY OF AUSTIN
All listed purposes: Recreation;Other.
Source: USACE National Inventory of Dams, NID ID TX01089 · Operator website · Matched by proximity (0.22 km)
Nearby Lakes in Travis County
Frequently asked questions about Walter E Long Lake Mid Lake
Where is Walter E Long Lake Mid Lake?
- Walter E Long Lake Mid Lake is a lake in Travis County, Texas. Its water-quality measurements are published by TCEQ and shown on this page as reported.
What is the water quality of Walter E Long Lake Mid Lake?
- Walter E Long Lake Mid Lake in Travis County, Texas has water-quality measurements published by TCEQ, shown here as reported. Water clarity: 3.6 ft visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 15.7 µg/L. Surface area: 1269 acres.
Is Walter E Long Lake Mid Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Walter E Long Lake Mid Lake across LakeQuality
10.1 mi away · 15 ft
10.3 mi away · cable-pulled, no boat wake
Species activity outlook by water temperature and season
Where to stay at Texas's top lakes, each with its readings
Texas's cleanest lakes, ranked on agency measurements
More lakes in Texas
Other Lakes in Texas
Eutrophic Lakes in Texas
Where this data comes from
28 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Texas Commission on Environmental Quality
TCEQMAIN28 samples · 2020–2024
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.