Mad Island Lake
Mad Island Lake in Matagorda County, Texas is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 862 acres.
- Area
- 862 acres
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Why Mad Island Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mad Island Lake, no water-quality sampling on record for this lake.
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by TCEQ and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Mad Island Lake is a 862-acre lake in Matagorda County, Texas.
Source: EPA Water Quality Portal sampling records, TCEQ, last sampled recent years. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Mad Island Lake
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay near Mad Island Lake
Compare lakeside cabins, hotels, and vacation rentals near Mad Island Lake in Matagorda 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 Mad Island Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 862 acres |
No bathymetric survey has been published for Mad Island Lake, so its depth is not documented here.
Fishing Mad Island Lake
Nearby Lakes in Matagorda County
Frequently asked questions about Mad Island Lake
Where is Mad Island Lake?
- Mad Island Lake is a lake in Matagorda County, Texas. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Mad Island Lake?
- Mad Island Lake in Matagorda County, Texas is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 862 acres.
Is Mad Island Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Mad Island Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
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Where this data comes from
Measurements for Mad Island Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.