33 cities · 1,157 graded lakes routed by road
How far is the nearest lake worth swimming in?
Pick your city. You get the closest graded lake, the closest one that earned an A, and the number of extra minutes between them. Sometimes that gap is nine minutes. Sometimes it is two hours, and that is worth knowing before you load the car.
The ranking is the water: clarity, phosphorus and algae, measured over years and reduced to a letter. Drive times are real road routing, not straight lines on a map.
Every city, and what clean water costs in minutes
| From | Closest lake | Closest A or B | Extra drive | A or B in range |
|---|---|---|---|---|
| Atlanta, GA | D 48 min · Lake Allatoona | B 3 hr · Lake Blackshear | +2 hr 12 min | 4 |
| Austin, TX | D 23 min · Walter E Long Lake Mid Lake | A 3 hr 54 min · Lake Cisco | +3 hr 31 min | 1 |
| Birmingham, AL | B 2 hr 10 min · Pool B | B 2 hr 10 min · Pool B | Same lake | 10 |
| Boston, MA | A 14 min · South Reservoir | A 14 min · South Reservoir | Same lake | 10 |
| Charlotte, NC | C 27 min · Mountain Island Lake | A 1 hr 45 min · Rockingham City Lake | +1 hr 18 min | 4 |
| Chicago, IL | D 29 min · Flatfoot Lake | A 32 min · Lake Opeka | +3 min | 15 |
| Cincinnati, OH | C 22 min · Doe Run Lake | A 2 hr 26 min · Marysville Upground Reservoir | +2 hr 4 min | 8 |
| Cleveland, OH | C 1 hr 45 min · Fremont Reservoir | B 1 hr 55 min · Powers Reservoir | +10 min | 14 |
| Columbus, OH | F 30 min · O'Shaughnessy Reservoir Lake | A 51 min · Marysville Upground Reservoir | +21 min | 4 |
| Dallas, TX | F 14 min · White Rock Lake | B 1 hr 52 min · Bois D'Arc Lake | +1 hr 38 min | 4 |
| Denver, CO | B 35 min · Chatfield Reservoir | B 35 min · Chatfield Reservoir | Same lake | 13 |
| Des Moines, IA | F 6 min · Grays Lake | A 17 min · Terra Park Lake | +11 min | 9 |
| Detroit, MI | B 42 min · Pleasant Lake | B 42 min · Pleasant Lake | Same lake | 23 |
| Houston, TX | D 28 min · Lake Houston | B 3 hr 33 min · Fairfield Lake | +3 hr 5 min | 2 |
| Indianapolis, IN | C 2 hr 24 min · Doe Run Lake | B 2 hr 58 min · Middle Lagoon Lake | +34 min | 7 |
| Kansas City, MO | F 4 min · Washington Lake | B 21 min · Waukomis Lake | +17 min | 7 |
| Louisville, KY | C 39 min · Long Run Lake | B 57 min · Freeman Lake | +18 min | 13 |
| Memphis, TN | D 16 min · Mckellar Lake | B 1 hr 13 min · Lower Lake | +57 min | 9 |
| Milwaukee, WI | B 33 min · Pewaukee Lake | B 33 min · Pewaukee Lake | Same lake | 27 |
| Nashville, TN | C 54 min · West Fork Drakes Reservoir | B 1 hr 41 min · Lake Malone | +47 min | 14 |
| Oklahoma City, OK | D 38 min · Wes Watkins Reservoir | B 3 hr 54 min · Bois D'Arc Lake | +3 hr 16 min | 1 |
| Omaha, NE | F 22 min · Lake Manawa | B 1 hr 6 min · Willow Lake | +44 min | 6 |
| Orlando, FL | B 2 min · Lake Lucerne West | B 2 min · Lake Lucerne West | Same lake | 18 |
| Philadelphia, PA | F 14 min · Newton Lake | A 24 min · Grenloch Lake | +10 min | 17 |
| Phoenix, AZ | B 25 min · Chaparral Park Lake | B 25 min · Chaparral Park Lake | Same lake | 2 |
| Pittsburgh, PA | D 1 hr 38 min · Salem Reservoir | B 3 hr 43 min · Powers Reservoir | +2 hr 5 min | 1 |
| Portland, OR | A 58 min · Henry Hagg Lake | A 58 min · Henry Hagg Lake | Same lake | 6 |
| Raleigh, NC | D 11 min · Lake Raleigh | B 1 hr 26 min · Old Town Reservoir | +1 hr 15 min | 4 |
| Richmond, VA | D 25 min · Ut To Chk Lake | B 48 min · Diascund Reservoir Off Dam | +23 min | 9 |
| Salt Lake City, UT | A 29 min · Little Dell Reservoir | A 29 min · Little Dell Reservoir | Same lake | 13 |
| Seattle, WA | C 1 hr 8 min · Weallup Lake | B 3 hr 23 min · Moses Lake | +2 hr 15 min | 1 |
| St. Louis, MO | D 5 min · Lafayette Park Lake | A 1 hr 1 min · Lake Wauwanoka | +56 min | 12 |
| Tampa, FL | D 8 min · Lake Roberta | B 14 min · Hillsborough-Silver Lake | +6 min | 14 |
Where clean water costs the most driving
In these cities the nearest water and the nearest good water are a long way apart. The closest lake is not a bad choice for an hour with a dog; it is a bad choice for a swim.
Where the closest lake is already the clean one
No tradeoff to make in these cities: the shortest drive and the best reachable water are the same lake.
How this was measured
Drive times and road miles are one-way road routing from each downtown to the nearest public road at each lake, over the OpenStreetMap network via OSRM (router.project-osrm.org) over OpenStreetMap, driving profile, free-flow. Nothing further than 4 hr was routed.
Only lakes carrying an A–F water-quality grade appear, because the letter is the only axis these pages rank on. A letter summarises years of phosphorus, nitrogen, chlorophyll-a and turbidity measurements; it describes the lake’s record, not conditions on a particular afternoon. Water clarity is shown beside it, not scored into it.
Plan the rest of the trip
Common questions
Frequently Asked Questions
Water quality and driving distance, and nothing else. Each city page lists the graded lakes you can reach by road, sorted by how long the drive takes, with the A–F water-quality letter beside every one. There is no nightly rate, no occupancy index and no popularity score in the ordering.
Because that is the decision. Somebody leaving a city on a Saturday morning is choosing between the water twenty minutes away and the water two hours away, and they cannot make that call if only one of the two is on the page. So both are, with the gap in minutes stated plainly.
Road routing from downtown to the nearest public road at each lake, over the OpenStreetMap road network. They are free-flow: no traffic model, no time of day, no stops. Treat them as a floor.
A city gets a page when there are at least three graded lakes it can reach by road, and at least one of them grades A or B. Where a metro is missing, it is usually because the monitoring record around it is thin rather than because the water is bad — no agency reported enough samples to put a letter on the nearby lakes.