Charles Mill Reservoir
Ashland County, Ohio1,350 acresView mapDirections
Ohio EPA publishes the water-quality measurements for Charles Mill Reservoir. Here is what has been measured.
- Public access
- Limited data
Charles Mill Reservoir in Ashland County, Ohio has water-quality measurements published by Ohio EPA, shown here as reported. Water clarity: 0.9 ft visibility. Surface area: 1350 acres.
Free interactive depth-contour map of Charles Mill Reservoir, reaching a maximum surveyed depth of 27 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Ohio DNR.
Charles Mill Reservoir is a 1,350-acre lake in Ashland County, Ohio. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Ohio EPA, last sampled 2021-10-11. Methodology: how these readings are compared.
Charles Mill Reservoir covers about 1,400 acres in Ashland County. It has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. For a place on the water, look through cabin and lake-house rentals near Charles Mill Reservoir on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Charles Mill Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
- Camping3 public campgrounds nearby
- Big water1,350 acres
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Charles Mill Reservoir is safe to swim in today is a call for the Ohio Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Charles Mill Reservoir
These are the measurements Ohio EPA publishes for Charles Mill Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 0.9 ft of visibility. TSI 79.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 79 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Charles Mill Reservoir
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Charles Mill Reservoir typically sits around 65°F at the surface in October. Summer average is about 78°F. Usually warmest in Aug (about 79°F) and coldest in Oct (about 65°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (65°F) to its warmest (79°F).
Typical surface water temperature by month, from 135 field readings (2010–2021) via the EPA Water Quality Portal. See the full Charles Mill Reservoir water temperature breakdown →
Lake Details
Surface area
1,350 acres
Public access
Yes
Listed by Ohio EPA
No bathymetric survey has been published for Charles Mill Reservoir, so its depth is not documented here.
Recreation & Access
- Charles Mill Boat RampPublic
- Charles Mill Lake Marina rampPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Charles Mill Reservoir
- Charles Mill Lake Park Main Campground0.3 km
- Charles Mill Lake Park Eagle Point Campground0.5 km
- Charles Mill Lake Park Beach Campground1.1 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Stays via Stay22
Stays near Charles Mill Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Charles Mill Reservoir in Ashland County, Ohio — 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 Charles Mill Reservoir
Prices for Oct 23–25, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Charles Mill Reservoir → · more Ohio lake trips
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Fishing Charles Mill Reservoir
Water quality readings over time
2 seasons of samples on record (2020–2021). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Reservoir Info (USACE NID)
Charles Mill Reservoir is a man-made reservoir impounded by the Charles Mill Dam (completed 1936), built primarily for flood risk reduction on the BLACK FORK OF MOHICAN RIVER; earth-type dam, 52 ft tall and 1,390 ft long.
- Surface area
- 1,350 ac
- Normal storage
- 7,400 ac-ft
- Max storage
- 88,000 ac-ft
- Drainage area
- 215 sq mi
- Hazard class
- High
- Owner
- USACE - Huntington District
All listed purposes: Flood Risk Reduction;Fish and Wildlife Pond;Recreation.
Source: USACE National Inventory of Dams, NID ID OH00020 · Operator website
Regulated Pollution Sources Nearby
4 EPA-permitted facilities operate within about 5 miles of Charles Mill Reservoir under Clean Water Act (NPDES) discharge permits. 4 facilities have a reported Clean Water Act violation in the past three years.
- Charles Mill Lake CampgroundMansfield · 0.4 mi away · NPDES OH0146650Recent violation
- Village Of Mifflin WwtpMifflin · 0.9 mi away · NPDES OH0146501Recent violation
- Mwcd - Johnny Appleseed WwtpAshland · 2.1 mi away · NPDES OH0130443Recent violation
- Village Of Lucas WwtpLucas · 4.9 mi away · NPDES OH0021041Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Ashland County
Frequently asked questions about Charles Mill Reservoir
Where is Charles Mill Reservoir?
- Charles Mill Reservoir is a lake in Ashland County, Ohio. Its water-quality measurements are published by Ohio EPA and shown on this page as reported.
What is the water quality of Charles Mill Reservoir?
- Charles Mill Reservoir in Ashland County, Ohio has water-quality measurements published by Ohio EPA, shown here as reported. Water clarity: 0.9 ft visibility. Surface area: 1350 acres.
Is Charles Mill Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Charles Mill Reservoir?
- Charles Mill Reservoir typically sits around 65°F at the surface in October, from 135 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
Are there boat ramps on Charles Mill Reservoir?
- Charles Mill Reservoir has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Charles Mill Boat Ramp, Charles Mill Lake Marina ramp. Public access is listed as yes.
Can I fish at Charles Mill Reservoir?
- Charles Mill Reservoir has 2 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Ohio's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Charles Mill Reservoir?
- Charles Mill Reservoir has 3 public campgrounds from USGS The National Map within 5 km, including Charles Mill Lake Park Main Campground, Charles Mill Lake Park Eagle Point Campground, Charles Mill Lake Park Beach Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Charles Mill Reservoir across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Ohio's top lakes, each with its readings
Ohio's cleanest lakes, ranked on agency measurements
More lakes in Ohio
Other Lakes in Ohio
Hypereutrophic Lakes in Ohio
Where this data comes from
39 measurements from 3 monitoring stations, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Ohio Lake Management Society (Volunteer)
OLMS39 samples · 2020–2021
Monitoring station identifiers (3)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory
Public campgrounds from USGS The National Map Structures, within about 3 miles