Green Castle Lake vs Rkcrk 5 Lake
Water quality, depth, fish species, and recreation comparison.
Green Castle Lake has a higher water quality grade (C, Fair) than Rkcrk 5 Lake (F, Very Poor). Both are in Wisconsin.
Both Green Castle Lake and Rkcrk 5 Lake sit in Iowa. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. Green Castle Lake (C) is materially cleaner than Rkcrk 5 Lake (F). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Green Castle Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Green Castle Lake
Murky, only visible to about 4.6 ft.
Rkcrk 5 Lake
Very murky, less than 1.1 ft of visibility.
Side-by-Side Metrics
| Metric | Green Castle Lake | Rkcrk 5 Lake |
|---|---|---|
| Overall Grade | C (Fair) | F (Very Poor) |
| Water Clarity | 4.6 ft | 1.1 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 6.9 µg/L | No data |
| Maximum Depth | - | - |
| Surface Area | 17 acres | 640 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | hypereutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Green Castle Lake wins on overall water quality with a Grade C versus Rkcrk 5 Lake's Grade F. Water clarity: 4.6 ft vs 1.1 ft. For fishing diversity, Green Castle Lake also leads with 0 species.