Sherman Reservoir
Sherman County, Nebraska2,868 acresView mapDirections
Nebraska DEE publishes the water-quality measurements for Sherman Reservoir. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- Public access
Sherman Reservoir in Sherman County, Nebraska has water-quality measurements published by Nebraska DEE, shown here as reported. Water clarity: 2.4 ft visibility. Phosphorus: 99.7 µg/L. Chlorophyll-a (algae): 4.4 µg/L. Surface area: 2868 acres.
Sherman Reservoir is a 2,868-acre mesotrophic lake in Sherman County, Nebraska. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 1 other monitored lakes in Sherman County, Sherman Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, NDEE, last sampled 2024-09-09. Methodology: how these readings are compared.
Sherman Reservoir covers about 2,900 acres in Sherman County. It has 3 public boat landings, so a lakefront rental is not the only way to get a boat on the water. Vrbo is where to look for cabins and lake homes around Sherman Reservoir, and Booking.com and Expedia search hotels near the lake for your dates.
What Sherman Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
- Camping1 public campground nearby
- Big water2,868 acres
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Sherman Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Sherman Reservoir is safe to swim in today is a call for the Nebraska Department of Environment and Energy and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Sherman Reservoir
These are the measurements Nebraska DEE publishes for Sherman 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 2.4 ft of visibility. Phosphorus 99.7 µg/L. Chlorophyll-a 4.4 µg/L. TSI 60.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 99.7µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 4.4µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 60 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Sherman Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
2,868 acres
Public access
Yes
Listed by Nebraska DEE
No bathymetric survey has been published for Sherman Reservoir, so its depth is not documented here.
Recreation & Access
- Marina BayPublic
- Thunder BayPublic
- Tradewinds MarinaSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Sherman Reservoir
- Sherman Reservoir State Recreation Area2.9 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 Sherman Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Sherman Reservoir in Sherman County, Nebraska — 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 Sherman Reservoir
Prices for Oct 30–Nov 1, 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 Sherman Reservoir → · more Nebraska lake trips
Follow Sherman Reservoir’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Sherman Reservoir
Water Quality Trend: Improving
Based on 13 years of monitoring (2012–2024).
Water clarity
Improving13 years
Phosphorus
Stable+1.86 µg/L/yr5 years
Chlorophyll-a
Improving-0.11 µg/L/yr12 years
Reservoir Info (USACE NID)
Sherman Reservoir is a man-made reservoir impounded by the Sherman Dam (completed 1962), built primarily for irrigation on the Oak Creek; earth-type dam, 134 ft tall and 4,450 ft long.
- Surface area
- 2,868 ac
- Normal storage
- 69,100 ac-ft
- Max storage
- 125,477 ac-ft
- Drainage area
- 37 sq mi
- Hazard class
- High
- Owner
- Farwell Irrigation District
Source: USACE National Inventory of Dams, NID ID NE01077 · Operator website
EPA Impairment Status
Sherman Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit NE-LO3-L0020 · Official waterbody report
Nearby Lakes in Sherman County
Frequently asked questions about Sherman Reservoir
Where is Sherman Reservoir?
- Sherman Reservoir is a lake in Sherman County, Nebraska. Its water-quality measurements are published by Nebraska DEE and shown on this page as reported.
What is the water quality of Sherman Reservoir?
- Sherman Reservoir in Sherman County, Nebraska has water-quality measurements published by Nebraska DEE, shown here as reported. Water clarity: 2.4 ft visibility. Phosphorus: 99.7 µg/L. Chlorophyll-a (algae): 4.4 µg/L. Surface area: 2868 acres.
Is Sherman Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Sherman Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Are there boat ramps on Sherman Reservoir?
- Sherman Reservoir has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Marina Bay, Thunder Bay, Tradewinds Marina. Public access is listed as yes.
Can I fish at Sherman Reservoir?
- Sherman Reservoir has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Nebraska's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Sherman Reservoir?
- Sherman Reservoir has 1 public campground from USGS The National Map within 5 km, including Sherman Reservoir State Recreation Area. 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 Sherman Reservoir across LakeQuality
More lakes in Nebraska
Other Lakes in Nebraska
Mesotrophic Lakes in Nebraska
Where this data comes from
173 measurements from 2 monitoring stations, 2012–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Nebraska Department of Environment and Energy
21NEB001_WQX173 samples · 2012–2024
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 447.0 ~ EPA; Chlorophyll a and b in phytoplankton by HPLC/UV
- Total Phosphorus After Block Digestion
Monitoring station identifiers (2)
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
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory
Public campgrounds from USGS The National Map Structures, within about 3 miles