Lake Sinai
Lake Sinai in Brookings County, South Dakota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1790 acres.
- Area
- 1,790 acres
- Public access
- Yes
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Why Lake Sinai has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Lake Sinai, no water-quality sampling on record for this lake.
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by SD DANR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Sinai is a 1,790-acre lake in Brookings County, South Dakota. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, SD DANR, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Lake Sinai water quality
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Lake Sinai
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay near Lake Sinai
Compare lakeside cabins, hotels, and vacation rentals near Lake Sinai in Brookings County, South Dakota — 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 Lake Sinai
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 1,790 acres |
| Public Access | Yes |
No bathymetric survey has been published for Lake Sinai, so its depth is not documented here.
Recreation & Access
- Sinai Public Water AccessPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake Sinai
Nearby Lakes in Brookings County
Frequently asked questions about Lake Sinai
Where is Lake Sinai?
- Lake Sinai is a lake in Brookings County, South Dakota. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Lake Sinai?
- Lake Sinai in Brookings County, South Dakota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1790 acres.
Is Lake Sinai safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Sinai is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Are there boat ramps on Lake Sinai?
- Lake Sinai has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Sinai Public Water Access. Public access is listed as yes.
Explore Lake Sinai across LakeQuality
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Where this data comes from
Measurements for Lake Sinai come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory