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LakeQuality
Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water

Data sources and attribution

LakeQuality only ingests a dataset when it has an SPDX licence on the allowlist and status = active. Confirm rows are listed so licence review cannot hide in a code comment. This page is generated from config/sources.json at build time — the Worker does not read the database for attribution.

How the readings are classified is on the methodology page. That page does not replace this one.

Currently used

EPA Water Quality Portal (epa-wqp)

  • Publisher: U.S. Environmental Protection Agency / USGS / NWQMC
  • Licence: CC0-1.0 — https://www.waterqualitydata.us/
  • Water-quality measurements from the Water Quality Portal (WQP), a cooperative service of the U.S. EPA, USGS, and the National Water Quality Monitoring Council. U.S. government works.
  • Landing page: https://www.waterqualitydata.us/

Ontario Lake Partner Program (ontario-lpp)

Ontario Broad-scale Monitoring (ontario-bsm)

Réseau de surveillance volontaire des lacs (quebec-rsvl)

EEA Bathing Water Directive (eea-bwd)

HydroLAKES (hydrolakes)

GLOBathy (globathy)

EPA Cyanobacteria Assessment Network (CyAN) (epa-cyan)

EPA ATTAINS 303(d) assessments (epa-attains)

  • Publisher: U.S. Environmental Protection Agency
  • Licence: US-PD — https://www.epa.gov/waterdata/attains
  • Clean Water Act §303(d) impairment decisions from EPA ATTAINS (Assessment, Total Maximum Daily Load Tracking and Implementation System). U.S. government work. A listing is the state's assessment of designated-use support, not an A–F water-quality letter.
  • Landing page: https://www.epa.gov/waterdata/attains

USGS National Water Information System (usgs-nwis)

  • Publisher: U.S. Geological Survey
  • Licence: US-PD — https://waterdata.usgs.gov/nwis
  • Live and recent water temperature and water-level readings from USGS NWIS instantaneous values (parameters 00010, 00065, 00062, 62614, 62615). U.S. government work. Dated snapshots; a missed fetch is not an all-clear.
  • Landing page: https://waterservices.usgs.gov/

USGS Nonindigenous Aquatic Species (usgs-nas)

  • Publisher: U.S. Geological Survey
  • Licence: US-PD — https://nas.er.usgs.gov/
  • Aquatic invasive-species occurrence records from the USGS Nonindigenous Aquatic Species database. U.S. government work. Presence is a documented occurrence, not a density or a grade.
  • Landing page: https://nas.er.usgs.gov/

LAGOS (Environmental Data Initiative) (lagos-edi)

  • Publisher: LAGOS / EDI
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • LAGOS-US, Environmental Data Initiative. Packages edi.854.1 (LOCUS) and edi.1043.1 (DEPTH). CC BY 4.0 confirmed 2026-09-26 against each package's EML intellectualRights, which reads "This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/)". The lake_depth table also carries 840 rows sourced from Navionics, a commercial provider; scripts/lib/lagos-locus.js excludes them by source name.
  • Landing page: https://portal.edirepository.org/

Nova Scotia lake water quality (ns-socrata)

British Columbia EnMoDS lake water quality (enmods-bc)

ECCC National Long-term Water Quality Monitoring (Newfoundland and Labrador lakes) (eccc-ltwqm)

USGS TNM Structures — Campgrounds (usgs-tnm-structures)

Recreation.gov RIDB facilities (recreation-gov-ridb)

  • Publisher: Recreation.gov / USDA / DOI
  • Licence: US-PD — https://www.recreation.gov/use-our-data
  • Federal recreation facility inventory from the Recreation Information Database (RIDB). Data Source: Recreation.gov. U.S. government work. Federal sites only; reservation URLs are the official recreation.gov facility id, never a guessed slug.
  • Landing page: https://ridb.recreation.gov/

Michigan DNR hydrography and lake deep points (mi-dnr-hydro)

USACE National Inventory of Dams (usace-nid)

  • Publisher: U.S. Army Corps of Engineers
  • Licence: US-PD — https://www.usa.gov/government-works
  • Dam and reservoir facts from the U.S. Army Corps of Engineers National Inventory of Dams (NID): dam name, year completed, height, length, dam type, primary purpose, the river impounded, surface area, storage capacity, hazard potential class, and owner. U.S. government work. A hazard potential class describes what lies downstream if the dam failed. It is not a statement about the dam's condition, and it says nothing about the quality of the water behind it.
  • Landing page: https://nid.sec.usace.army.mil/

USGS Boat Ramp Locations in the United States (usgs-boat-ramps)

USGS GNIS Feature Description History (usgs-gnis-descriptions)

  • Publisher: U.S. Geological Survey / U.S. Board on Geographic Names
  • Licence: US-PD — https://prd-tnm.s3.amazonaws.com/StagedProducts/GeographicNames/Topical/FeatureDescriptionHistory_National_Text.xml
  • Maximum lake depth transcribed from the GNIS feature-description text (feature_id | description | history; 189,911 rows, 4.2 MB). Licence read verbatim from this product’s own FGDC sidecar: Access_Constraints "None"; Use_Constraints "None. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data." MEASURED — these are survey figures written into GNIS by the USGS/BGN, so they land in physical.maxDepthFt, the surveyed tier src/lib/depth.ts prefers over the HydroLAKES model. The file carries no per-row citation of WHICH survey, so data/gnis-depth.json holds the feature id and the exact sentence behind every published number. Joins on feature_id = the corpus gnisId after numeric normalisation (the corpus zero-pads to 8 chars, GNIS does not). 1,055 lakes gained a maximum depth that had none — WI 648, MI 155, MN 150, AK 46, across 18 states. Where a record already carried a depth from another source the incumbent wins and nothing is overwritten; on those 1,208 overlapping features GNIS agrees to the foot on 62.7% and within 10% on 79.4%, which is the only outside check on the prose extraction.
  • Landing page: https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/GeographicNames/

Licensed, not yet on the live map

We have permission to use these sources and have started processing them, but their lakes are not published yet. Nothing below appears on the map, in a ranking, or in search results until its coverage is complete enough to stand on its own.

USACE CWMS project pool elevations (usace-cwms)

  • Publisher: U.S. Army Corps of Engineers
  • Licence: US-PD — https://www.usa.gov/government-works
  • Reservoir pool elevations and the Corps of Engineers' own named reference levels (conservation pool, guide curve, normal pool) from the CWMS Data API. U.S. government work. Each elevation is on its project's NATIVE vertical datum, so a reading and its reference are only comparable to each other: they are not comparable to a mapped surface elevation or to a USGS figure on a different datum. A conservation pool is frequently a seasonal rule curve rather than a fixed number, so the reference shown is the one in effect on the date given. Dated snapshots; a missed fetch is not an all-clear.
  • Landing page: https://cwms-data.usace.army.mil/

Taiwan MOENV reservoir water quality (moenv-tw)

  • Publisher: Ministry of Environment (Taiwan)
  • Licence: Taiwan-OGDL-1.0 — https://data.gov.tw/license
  • Taiwan MOENV reservoir water-quality monitoring (WQX_P_117). Open Government Data License, version 1.0 (https://data.gov.tw/license), compatible with CC BY 4.0. Attribution: Ministry of Environment (Taiwan).
  • Landing page: https://data.moenv.gov.tw/

Finland SYKE VESLA surface water quality (syke-vesla)

Estonia KESE environmental monitoring (kese-ee)

England Environment Agency Water Quality Archive (ea-wqa)

Lithuania AAA lake state monitoring (aaa-lt)

Japan MOE public water-body monitoring (lakes) (moe-jp)

Northern Ireland DAERA lake nutrient monitoring (daera-ni)

ARPA Lombardia lake monitoring (arpa-lom)

ARPA Veneto lake monitoring (arpa-ven)

Arpae Emilia-Romagna lake monitoring (arpae-er)

ARPA Umbria lake monitoring (arpa-umb)

Poland GIOŚ lake water-quality monitoring (gios-pjwp)

UNEP GEMS/Water Global Freshwater Quality Archive (gemstat-gfqa)

  • Publisher: UNEP GEMS/Water Data Centre / International Centre for Water Resources and Global Change
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • In-situ lake and reservoir water-quality measurements (total phosphorus, chlorophyll-a, and Secchi transparency; 2016 onward) from the UNEP GEMS/Water Global Freshwater Quality Archive v3 (DOI 10.5281/zenodo.18459694), the OPEN slice equivalent to CC BY 4.0. Heinle, Lisniak, Saile (2026). National Hydrological Services of UN Member States provided the underlying observations. Limited / CC BY-NC GEMStat rows are not used.
  • Landing page: https://doi.org/10.5281/zenodo.18459694

EPA Ireland WFD Cycle 3 lake waterbodies (epa-ie-wfd-lakes)

CSIRO bio-optical data for Australian inland waters (csiro-inland-biooptical)

  • Publisher: CSIRO
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • In-situ Secchi depth and HPLC chlorophyll-a measurements (inland lakes and reservoirs only; 2016 onward) from CSIRO Data Access Portal collection 54602, Bio-optical data for Australian Inland Waters v.1 (DOI 10.25919/rtd7-j815). Anstee, Drayson, Botha, Kerrisk, Sagar, Ford, Wojtasiewicz, Clementson, Byrne (2022). CC BY 4.0.
  • Landing page: https://data.csiro.au/collection/csiro:54602v1

LAWA lake water quality (lawa-nz)

  • Publisher: Land Air Water Aotearoa (regional councils, MfE, Cawthron)
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • Lake water-quality samples from Land Air Water Aotearoa (LAWA) and partner regional / unitary councils. Creative Commons Attribution 4.0 International (CC BY 4.0). Attribution: LAWA and the relevant partner agency. Do not ingest LakeSPI (separate CC BY-NC 3.0 product).
  • Landing page: https://www.lawa.org.nz/download-data

PANGAEA GLORIA inland-lake matchup (Lehmann et al. 2022) (pangaea-gloria)

NIER national water-quality network (lakes / 호소) (nier-kr)

  • Publisher: National Institute of Environmental Research (Korea)
  • Licence: Korea-PDA — https://www.data.go.kr/data/15111319/fileData.do
  • National inland-lake (호소) water-quality monitoring from the National Institute of Environmental Research / Ministry of Climate, Energy and Environment (Korea), data.go.kr file 15111319. Public Data Act unrestricted reuse (이용허락범위 제한 없음 / 제0유형). Factory SPDX Korea-PDA — same class of national-terms mapping as Japan-GSTU-2.0. Attribution: 국립환경과학원.
  • Landing page: https://www.data.go.kr/data/15111319/fileData.do

URA / UBEGI Basque reservoir water quality (ura-es)

PANGAEA twelve Mediterranean reservoirs, southern Spain (pangaea-andalucia)

Eawag long-term Swiss lake monitoring (eawag-ch)

Rijkswaterstaat WaterWebservices inland waters (rws-nl)

Hub'Eau / Naïades plans d'eau water quality (hubeau-fr)

LfU Bayern GKD lake chemistry (gkd-by)

  • Publisher: Bayerisches Landesamt für Umwelt (LfU) — Gewässerkundlicher Dienst Bayern
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • Lake water-quality measurements (total phosphorus, chlorophyll-a, and Secchi) from the Gewässerkundlicher Dienst Bayern, Bayerisches Landesamt für Umwelt. Creative Commons Attribution 4.0 International. Named inland lakes and reservoirs only.
  • Landing page: https://www.gkd.bayern.de/de/seen/chemie

Michigan Inland Lakes Water Clarity (2018-2023) (mi-egle-clarity)

  • Publisher: Michigan Department of Environment, Great Lakes, and Energy (EGLE)
  • Licence: US-PD — https://gis-michigan.opendata.arcgis.com/maps/egle::michigan-inland-lakes-water-clarity-2018-2023
  • Satellite-derived Secchi clarity, chlorophyll-a and coloured dissolved organic matter for 6,524 Michigan inland lakes, monthly May-October 2018-2023, published by EGLE with a per-lake per-year count of valid observations. The polygon layer also carries lake area, mean and maximum depth, shoreline length, county and ecoregion. Michigan publishes it as a public service with no restrictions on use, reproduction or distribution. REMOTELY SENSED, not in-situ sampling: disclose origin on any page that shows it, and do not blend it into an A-F letter without a satellite grading framework.
  • Landing page: https://gis-michigan.opendata.arcgis.com/

USGS National Hydrography Dataset — NHDWaterbody (nhd)

CDFW California Lakes (cdfw)

USGS Protected Areas Database of the United States (PAD-US) (usgs-padus)

LAGOS-US LOCUS v1.0 — lake identifiers and location (lagos-us-locus)

  • Publisher: Environmental Data Initiative (EDI) — Cheruvelil, Soranno et al.
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • LAGOS-US LOCUS v1.0 (EDI packageId edi.854.1). The CROSSWALK module: lake_nhdid IS an NHD Permanent_Identifier and lagoslakeid is the key every other LAGOS module uses, so this package is the bridge from our xref.nhd to LAGOS. 479,950 lakes. Licence read verbatim from <intellectualRights>: "This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use." Read via the DataONE GMN node (PASTA readMetadata 403s anonymously). Join audited 2026-09-24 against 25,484 live pages: name agrees 98.7%, centroid p50 82 m / p90 515 m, only 12 pages (0.047%) differ in name AND sit over 1 km apart.
  • Landing page: https://portal.edirepository.org/nis/mapbrowse?packageid=edi.854.1

LAGOS-US DEPTH v1.0 — maximum and mean lake depth (lagos-us-depth)

  • Publisher: Environmental Data Initiative (EDI) — Stachelek, Soranno et al.
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • LAGOS-US DEPTH v1.0 (EDI packageId edi.1043.1), lake_depth.csv, 17,675 rows. IN-SITU compiled depth, not modelled: lake_maxdepth_m and lake_meandepth_m in metres with lake_depth_sourcename / lake_depth_sourceurl naming the originating survey per row, and lake_maxdepth_effort / lake_meandepth_effort describing how it was obtained. Every row carries a max depth. Joins 6,950 of our live lake pages through LOCUS. Licence read verbatim from <intellectualRights>: "This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use." This is the largest single answer to the depth gap: 30,747 thin pages carry no depth, and GLOBathy can publish on only 78 of them.
  • Landing page: https://portal.edirepository.org/nis/mapbrowse?packageid=edi.1043.1

LAGOS-US RESERVOIR v1.0 — natural lake vs reservoir class (lagos-us-reservoir)

  • Publisher: Environmental Data Initiative (EDI) — Polus, Soranno et al.
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • LAGOS-US RESERVOIR v1.0 (EDI packageId edi.1016.2). Natural-lake vs reservoir class. Licence read verbatim from <intellectualRights>: "This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use." MOSTLY MODELLED AND MUST BE LABELLED SO: measured on our own join, 20,920 of 25,472 matching rows (82.1%) carry lake_rsvr_classmethod="predicted". Any reader-facing use ships origin="modelled" with confidence capped at moderate, the same contract the satellite-clarity surface already honours, and never as a measurement.
  • Landing page: https://portal.edirepository.org/nis/mapbrowse?packageid=edi.1016.2

LAGOS-US HUMAN v1.0 — public access and lakeshore human context (lagos-us-human)

  • Publisher: Environmental Data Initiative (EDI) — Smith, Soranno et al.
  • Licence: CC-BY-4.0 — https://creativecommons.org/licenses/by/4.0/
  • LAGOS-US HUMAN v1.0 (EDI packageId edi.2069.1), lake_access.csv, 479,950 rows, 20.1 MB. PUBLIC ACCESS, the second gap: lake_publicboatlaunch_yn, buff100_trails_yn, buff100_publiclands_pct, buff500_publiclands_pct, lake_primaryroaddistance_m. 44,985 of the 479,950 lakes carry a positive access fact. Ceiling of 25,484 of our pages via the LOCUS join; 8,778 of those also carry a DEPTH row, so the two compound. Licence read verbatim from <intellectualRights>: "This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use." CONUS ONLY — zero rows for AK, HI and PR, so it does nothing for Alaska 2,463 thin pages.
  • Landing page: https://portal.edirepository.org/nis/mapbrowse?packageid=edi.2069.1

Satellite products

No satellite water-quality product measures Secchi depth. Values labelled Secchi in a satellite archive are derived from turbidity or diffuse attenuation (Kd). Copernicus CLMS Lakes covers on the order of 4,200 lakes globally, not every HydroLAKES polygon. CLMS v1 and v2 turbidity are not a continuous time series — do not splice them into one trend. Satellite values, where they ever appear, are marked as satellite-derived beside the reading so they cannot be mistaken for an in-water sample. They are not ingested yet.

Not yet licensed for ingest

These rows are status = confirm. Loaders refuse them until a human writes the SPDX string and flips them to active.