About PlainLakes
Our mission is to make official water-quality assessments and water-level records for U.S. lakes and reservoirs easy to find and easy to read. PlainLakes helps anglers, swimmers, boaters, lakefront residents, researchers, and journalists look up what the responsible agency has actually reported about a waterbody, without paywalls or account requirements.
PlainLakes publishes a reference page for each covered waterbody. A page shows the reported water-quality assessment status (Fully Supporting or Not Supporting its designated uses), the reported impairment causes such as mercury, nutrients, or pathogens, the use-by-use verdicts for fish consumption, recreation, and aquatic life, recent water-level records where a monitoring gage exists, and the name of the government that filed the assessment.
Our Data
PlainLakes compiles records from two official federal data systems:
- EPA ATTAINS: Integrated Report assessment decisions submitted to the U.S. Environmental Protection Agency under Clean Water Act sections 303(d) and 305(b), by states and by tribal nations administering the program for their own waters. This covers assessment status, designated-use support verdicts, and impairment causes.
- USGS National Water Information System (NWIS): daily lake and reservoir water-surface elevation, reservoir storage, and gage height observations for the trailing 365 days. Water-level readings on PlainLakes are daily-batch snapshots, never real-time.
Methodology
PlainLakes downloads the source records from EPA and USGS, loads them into a structured database, and renders every page from that database. No value is modified, interpolated, or editorialized. For full details on processing, coverage, and limitations, see the methodology page.
Updates
Assessment decisions are made by the environmental agency of the government that reports the waterbody and submitted to EPA on reporting cycles that are typically every 2 years, and some agencies lag behind that schedule. Water-level observations from USGS NWIS are refreshed in daily batches. Each page shows the vintage of the data it displays and names the government that filed it.
Coverage
PlainLakes covers the lake-type waterbodies that a state or tribal government has reported to EPA ATTAINS under the Clean Water Act from the 50 states and the District of Columbia. That register is the whole corpus: it is not a census of every lake in the United States. USGS water-level records are matched onto waterbodies that are already in that register, so a gauge adds a water level to a lake PlainLakes covers — it never adds the lake. A lake that USGS monitors but no agency has reported to EPA does not appear here. ATTAINS also carries assessment units an agency has retired — closed permanently, usually because the water was re-divided into new units assessed in its place. Every total on this site counts the current register only, because a retired unit and the units that replaced it would otherwise count the same water twice. Retired units keep their pages, which say so, and each state page reports how many it has. If a lake is missing, no agency has reported it to EPA for this cycle. If it appears without an assessment status, it was reported but not assessed. Neither means its water is clean or polluted — an unassessed lake is simply one nobody has judged.
Not Affiliated
PlainLakes is not affiliated with the U.S. Environmental Protection Agency, the U.S. Geological Survey, or any state, tribal, or federal government whose records appear here. PlainLakes is an independent data portal that presents public records in a more accessible format.
Who Built This
PlainLakes is an independent publisher that compiles public water-quality and water-level records into plain-language reference pages. The editorial work goes into the pipeline: how records are sourced, matched to waterbodies, and presented, and into keeping the published pages faithful to the source data. PlainLakes does not accept compensation from any agency, utility, or business connected to the waterbodies it covers.
Editorial Standards
Pages are produced programmatically from official government records. Assessment verdicts and water-level figures are loaded directly from EPA ATTAINS and USGS NWIS and are never altered. The methodology page documents where each figure comes from, and corrections are welcome through the contact page or at corrections@plainlakes.com.
Important Disclaimer
This site is for informational purposes only and does not provide medical or safety advice. A fish-consumption use status from an assessment is a starting point, not guidance on what is safe to eat. Before eating fish from any lake, consult the applicable fish advisory program, run by your state health or environmental agency or by the tribal government with jurisdiction over those waters, which issues species-specific limits and separate limits for children and pregnant women. For swimming and recreation, follow posted closures and current advisories from local health authorities, which can change faster than assessment records.
Contact
For questions or feedback, email hello@plainlakes.com or use our contact page. For data corrections, email corrections@plainlakes.com.
Who Publishes This
PlainLakes is operated by Kiznis Studio, an independent data-engineering studio (solo-operated). Questions, corrections, and accountability inquiries can be sent to hello@plainlakes.com.