Lake Del Valle
Lake Del Valle in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 7 ft visibility. Surface area: 710 acres.
- Clarity
- 7 ft
- Area
- 710 acres
- Public access
- Yes
Why Lake Del Valle has no grade
We grade a lake only when its monitoring record clears the evidence bar: 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 Del Valle, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
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 your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Del Valle is a 710-acre lake in Alameda County, California. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-07-28. Grade methodology: LakeGrade methodology.
Watch Lake Del Valle water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Lake Del Valle
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 7 ft. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Lake Del Valle
Compare lakeside cabins, hotels, and vacation rentals near Lake Del Valle in Alameda County, California — 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 Del Valle
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 710 acres |
| Public Access | Yes |
No bathymetric survey has been published for Lake Del Valle, so its depth is not documented here.
Recreation & Access
- Del Valle LakePublic
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
Fishing Lake Del Valle
Reservoir Info (USACE NID)
Lake Del Valle is a man-made reservoir impounded by the Del Valle (completed 1968), built primarily for flood risk reduction on the Arroyo Valle; earth-type dam, 222 ft tall and 880 ft long.
- Surface area
- 710 ac
- Max storage
- 77,100 ac-ft
- Drainage area
- 146 sq mi
- Hazard class
- High
- Owner
- California Department of Water Resources
All listed purposes: Flood Risk Reduction;Irrigation;Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID CA00043 · Operator website
EPA Impairment Status
Lake Del Valle is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit CAL2043002420050519181540 · Official waterbody report
Nearby Lakes in Alameda County
Frequently asked questions about Lake Del Valle
Where is Lake Del Valle?
- Lake Del Valle is a lake in Alameda County, California. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Lake Del Valle?
- Lake Del Valle in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 7 ft visibility. Surface area: 710 acres.
Is Lake Del Valle safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Del Valle 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 Del Valle?
- Lake Del Valle has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Del Valle Lake. Public access is listed as yes.
Explore Lake Del Valle across LakeGrade
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Where this data comes from
5 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- North American Lake Management Society
NALMS5 samples · 2022–2023
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