Rock Creek Beach Lake
Jasper County, Iowa640 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Rock Creek Beach Lake. Here is what has been measured.
- Public access
- Limited data
Rock Creek Beach Lake in Jasper County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.1 ft visibility. Surface area: 640 acres.
Free interactive depth-contour map of Rock Creek Beach Lake, reaching a maximum surveyed depth of 16 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Rock Creek Beach Lake is a 640-acre lake in Jasper County, Iowa. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-08-27. Methodology: how these readings are compared.
Rock Creek Beach Lake covers about 640 acres in Jasper County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Rock Creek Beach Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Rock Creek Beach Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingBacteria tested: exceedances
Based on E. coli testing, Rock Creek Beach Lake occasionally exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 7.5% of 106 samples across 7 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Iowa’s current beach and health-department advisories before swimming.
Whether Rock Creek Beach Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rock Creek Beach Lake
These are the measurements Iowa DNR publishes for Rock Creek Beach Lake, 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 1.1 ft of visibility. TSI 75.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.1ft | 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. | 75 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Rock Creek Beach Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Rock Creek Beach Lake typically sits around 79°F at the surface in August. Summer average is about 79°F. Usually warmest in Jul (about 82°F) and coldest in May (about 68°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (68°F) to its warmest (82°F).
Typical surface water temperature by month, from 79 field readings (2010–2022) via the EPA Water Quality Portal. See the full Rock Creek Beach Lake water temperature breakdown →
Lake Details
Surface area
640 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Rock Creek Beach Lake, so its depth is not documented here.
Recreation & Access
- Rock Creek WestPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Rock Creek Beach Lake
Compare lakeside cabins, hotels, and vacation rentals near Rock Creek Beach Lake in Jasper County, Iowa — 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 Rock Creek Beach Lake
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Fishing Rock Creek Beach Lake
Water Quality Trend: Improving
Based on 5 years of monitoring (2020–2024).
Water clarity
Improving5 years
Phosphorus
Improving-12.2 µg/L/yr4 years
Chlorophyll-a
Improving-2.11 µg/L/yr5 years
Reservoir Info (USACE NID)
Rock Creek Beach Lake is a man-made reservoir impounded by the Rock Creek Dam, built primarily for recreation on the ROCK CREEK; earth-type dam, 33 ft tall and 1,500 ft long.
- Surface area
- 640 ac
- Normal storage
- 5,500 ac-ft
- Max storage
- 13,700 ac-ft
- Drainage area
- 41.4 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA00537 · Operator website · Matched by proximity (0.53 km)
Nearby Lakes in Jasper County
Frequently asked questions about Rock Creek Beach Lake
Where is Rock Creek Beach Lake?
- Rock Creek Beach Lake is a lake in Jasper County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Rock Creek Beach Lake?
- Rock Creek Beach Lake in Jasper County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.1 ft visibility. Surface area: 640 acres.
Is Rock Creek Beach Lake safe to swim in?
- Based on E. coli testing, Rock Creek Beach Lake occasionally exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 7.5% of 106 samples across 7 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Rock Creek Beach Lake is safe to swim in today is a call for Iowa's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Rock Creek Beach Lake?
- Rock Creek Beach Lake typically sits around 79°F at the surface in August, from 79 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
Are there boat ramps on Rock Creek Beach Lake?
- Rock Creek Beach Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Rock Creek West. Public access is listed as yes.
Can I fish at Rock Creek Beach Lake?
- Rock Creek Beach Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Iowa's fish and wildlife agency, so check its current regulations before you go.
Explore Rock Creek Beach Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
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Where this data comes from
44 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX44 samples · 2021–2024
Analytical methods
- Unknown
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (1)
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
Named boat-access points from the USGS National Boat Ramps inventory