Collect, share, and explore community water science data
We’re a non-profit on a mission to make water science accessible! Our free, open-access platform, testing equipment, and training resources help communities collect, organize, and share water quality data.
Popular testing spots
›Recently sampled and photographed
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Blackberry Creek Hannaford Woods FP, 28 February 2026
Dataset: Winter Chloride Watch -
Blackberry Creek Hannaford Woods FP, 28 February 2026
Dataset: Winter Chloride Watch -
West Branch DuPage River, 28 February 2026
Dataset: Winter Chloride Watch -
West Branch DuPage River, 28 February 2026
Dataset: Winter Chloride Watch -
West Branch DuPage River, 28 February 2026
Dataset: Winter Chloride Watch -
Salt Creek Greenway Trail (just south of North Avenue), 28 February 2026
Dataset: Winter Chloride Watch -
Salt Creek Greenway Trail (just south of North Avenue), 28 February 2026
Dataset: Winter Chloride Watch -
Salt Creek Greenway Trail (just south of North Avenue), 28 February 2026
Dataset: Winter Chloride Watch -
Salt Creek Greenway Trail (just south of North Avenue), 28 February 2026
Dataset: Winter Chloride Watch -
Downers Grove , 28 February 2026
Dataset: Winter Chloride Watch -
Pioneer Park Canoe launch, 28 February 2026
Dataset: Water Rangers Water Quality Testers -
West Branch Dupage River, 28 February 2026
Dataset: Winter Chloride Watch
Most active datasets
Active this week
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Winter Chloride Watch
Part of the organization: National Great Rivers
📊 7,425 observations total
🧪 37.5K readings total
⏱ 50 observations this week
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Lake Erie Rangers Monthly Monitoring
Part of the organization: Lake Erie Rangers
📊 929 observations total
🧪 15.3K readings total
⏱ 27 observations this week
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Lea Guardians
Part of the organization: Thames21
📊 2,126 observations total
🧪 20.8K readings total
⏱ 19 observations this week
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Roundhay Freshwater Watch
Part of the organization: Roundhay Environmental Action Project and Friends of Roundhay Park
📊 173 observations total
🧪 3,522 readings total
⏱ 12 observations this week
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Roding Beam and Ingrebourne
Part of the organization: Thames21
📊 301 observations total
🧪 1,306 readings total
⏱ 10 observations this week
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Burke Mountain Naturalists
Part of the organization: Burke Mountain Naturalists
📊 303 observations total
🧪 3,897 readings total
⏱ 8 observations this week
Latest observations
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Blackberry Creek Hannaford Woods FP
28 February 2026
- Blackberry Creek at Hannaford Woods FP, Illinois, United States
- Dataset: Winter Chloride Watch
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Ruisseau Place du Parc Saint-Lazare
28 February 2026
- Décharge Saint-Lazare, Quebec, Canada
- Dataset: Conseil du bassin versant de la région de Vaudreuil-Soulanges
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West Branch DuPage River
28 February 2026
- DuPage River, Illinois, United States
- Dataset: Winter Chloride Watch
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Salt Creek Greenway Trail (just south of North Avenue)
28 February 2026
- Salt Creek, Illinois, United States
- Dataset: Winter Chloride Watch
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Downers Grove
28 February 2026
- Prentiss Creek , Illinois, United States
- Dataset: Winter Chloride Watch
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Pioneer Park Canoe launch
28 February 2026
- West DuPage River, Illinois, United States
- Dataset: Water Rangers Water Quality Testers
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West Branch Dupage River
28 February 2026
- WBDR, Illinois, United States
- Dataset: Winter Chloride Watch
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Mill Creek at bike trail bridge
28 February 2026
- Mill Creek, Illinois, United States
- Dataset: Winter Chloride Watch
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Creek under Fairmount Ave, east side of bridge
28 February 2026
- Creek under Fairmount Ave, Illinois, United States
- Dataset: Winter Chloride Watch
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North Aurora Riverfront Park
28 February 2026
- Fox River, Illinois, United States
- Dataset: Winter Chloride Watch
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Flood Relief Channel outflow
28 February 2026
- Old Lea, Waltham Forest, United Kingdom
- Dataset: Lea Guardians