Chalkrock Lake
Cedar County, Nebraska44 acresView mapDirections
Clarity, phosphorus, and algae sit in the clean band for this region.
↑ up from C at the last regrade
- Eutrophic
- Impaired · Algal growth
- #1 of 2 in the county
- Public access
- Limited data
Chalkrock Lake in Cedar County, Nebraska has a water quality grade of B (Good). Water clarity: 3.3 ft visibility. Chlorophyll-a (algae): 9.3 µg/L. Surface area: 44 acres.
- Clarity
- 3.3 ft
- Area
- 44 acres
- Type
- Eutrophic
- Chlorophyll-a
- 9.3 µg/L
- Public access
- Yes
Stays via Stay22
Stays near Chalkrock Lake
Compare lakeside cabins, hotels, and vacation rentals near Chalkrock Lake in Cedar 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 Chalkrock Lake
Prices for Sep 11–13, 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 whole trip? See where to stay at Nebraska’s top lakes →
Watch Chalkrock Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Chalkrock Lake is a 44-acre productive, nutrient-rich eutrophic lake in Cedar County, Nebraska. Water quality is graded B based on 1 sampling years through 2016. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Cedar County, Chalkrock Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, NDEE, last sampled 2016-09-21. Grade methodology: LakeQuality methodology.
What Chalkrock Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The B is nutrients and algae, not a swimming clearance. Chalkrock Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Water Quality Grade: B (Good)
Very murky, less than 3.3 ft of visibility. Chlorophyll-a 9.3 µg/L. TSI 56. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 9.3 µg/L | Good |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 44 acres |
| Public Access | Yes |
No bathymetric survey has been published for Chalkrock Lake, so its depth is not documented here.
Recreation & Access
- Chalkrock Wildlife Management AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Chalkrock Lake
Reservoir Info (USACE NID)
Chalkrock Lake is a man-made reservoir impounded by the Menominee Dam (completed 1986), built primarily for flood risk reduction on the Antelope Creek; earth-type dam, 61 ft tall and 2,054 ft long.
- Surface area
- 44 ac
- Normal storage
- 291 ac-ft
- Max storage
- 3,198.1 ac-ft
- Drainage area
- 18 sq mi
- Hazard class
- Low
- Owner
- Lewis & Clark Natural Resources District
Source: USACE National Inventory of Dams, NID ID NE02258 · Operator website · Matched by proximity (0.17 km)
EPA Impairment Status
Chalkrock Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit NE-MT2-L0020 · Official waterbody report
County Ranking
Ranked #1 of 2 lakes in Cedar County
Nearby Lakes in Cedar County
Frequently asked questions about Chalkrock Lake
Where is Chalkrock Lake?
- Chalkrock Lake is a lake in Cedar County, Nebraska. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Chalkrock Lake?
- Chalkrock Lake in Cedar County, Nebraska has a water quality grade of B (Good). Water clarity: 3.3 ft visibility. Chlorophyll-a (algae): 9.3 µg/L. Surface area: 44 acres.
Is Chalkrock Lake safe to swim in?
- The B is nutrients and algae, not a swimming clearance. Chalkrock Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Are there boat ramps on Chalkrock Lake?
- Chalkrock Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Chalkrock Wildlife Management Area. Public access is listed as yes.
Explore Chalkrock Lake across LakeQuality
More Nebraska Lake Rankings
Other Grade B Lakes in Nebraska
Eutrophic Lakes in Nebraska
Where this data comes from
10 measurements from 1 monitoring station, 2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Nebraska Department of Environment and Energy
21NEB001_WQX10 samples · 2016
Analytical methods
- 447.0 ~ EPA; Chlorophyll a and b in phytoplankton by HPLC/UV
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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