Silver Lake Max Depth
Delaware County, Iowa39 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Oxygen depletion (low DO)
- #1 of 1 in the county
- 27 ft max depth
- Public access
Silver Lake Max Depth in Delaware County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 2.4 ft visibility. Phosphorus: 152 µg/L. Chlorophyll-a (algae): 37.6 µg/L. Surface area: 39 acres.
- Clarity
- 2.4 ft
- Typical in September
- 71°F
- Max depth
- ~27 ft est.
- Area
- 39 acres
- Type
- Hypereutrophic
- Phosphorus
- 152 µg/L
- Chlorophyll-a
- 37.6 µg/L
- Trend
- → Stable
- Public access
- Yes
Stays via Stay22
Stays near Silver Lake Max Depth
Compare lakeside cabins, hotels, and vacation rentals near Silver Lake Max Depth in Delaware 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Silver Lake Max Depth are listed below.
Top-rated places to stay near Silver Lake Max Depth
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Free interactive depth-contour map of Silver Lake Max Depth, reaching a maximum surveyed depth of 16 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Silver Lake Max Depth is a 39-acre highly nutrient-loaded hypereutrophic lake in Delaware County, Iowa with an estimated average depth of about 27 feet. Water quality is graded F based on 2 sampling years through 2024. Phosphorus level is improving over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-10-21. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyAlgae risk
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 F is nutrients and algae, not a swimming clearance. Silver Lake Max Depth is listed impaired under Clean Water Act §303(d) (IR 4A) for oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.4 ft of visibility. Phosphorus 152 µg/L. Chlorophyll-a 37.6 µg/L. TSI 69. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.4 ft | Not graded |
| Phosphorus | 152 µg/L | Poor |
| Chlorophyll-a (Algae) | 37.6 µg/L | Poor |
| Trophic State Index (TSI) | 69 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Silver Lake Max Depth typically sits around 71°F at the surface in September. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in Sep (about 71°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 26 field readings (2010–2023) via the EPA Water Quality Portal. See the full Silver Lake Max Depth water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~27 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 39 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Iowa has not published bathymetry for Silver Lake Max Depth.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Silver Lake Max Depth
Water Quality Trend: → Stable
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.015 m/yr | 4 |
| Phosphorus | ↑ Improving | -14.9 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +21.39 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Silver Lake Max Depth is a man-made reservoir impounded by the Silver Lake Dam (completed 1948), built primarily for recreation on the TR-MAQUOKETA RIVER; earth-type dam, 25 ft tall and 200 ft long.
- Surface area
- 39 ac
- Normal storage
- 210 ac-ft
- Max storage
- 415 ac-ft
- Drainage area
- 0.4 sq mi
- Hazard class
- Low
- Owner
- Delaware County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA02035 · Operator website · Matched by proximity (0.15 km)
EPA Impairment Status
Silver Lake Max Depth is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 01-MAQ-17 · Official waterbody report · Matched by proximity (0.27 km)
County Ranking
Ranked #1 of 1 lakes in Delaware County
Nearby Lakes With Higher Grades
Silver Lake Max Depth holds Grade F. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Delaware County
Frequently asked questions about Silver Lake Max Depth
Where is Silver Lake Max Depth?
- Silver Lake Max Depth is a lake in Delaware County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Silver Lake Max Depth?
- Silver Lake Max Depth in Delaware County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 2.4 ft visibility. Phosphorus: 152 µg/L. Chlorophyll-a (algae): 37.6 µg/L. Surface area: 39 acres.
Is Silver Lake Max Depth safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Silver Lake Max Depth is listed impaired under Clean Water Act §303(d) (IR 4A) for oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
What is the water temperature of Silver Lake Max Depth?
- Silver Lake Max Depth typically sits around 71°F at the surface in September, from 26 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Silver Lake Max Depth?
- No published bathymetric survey covers Silver Lake Max Depth, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 27 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 39 acres.
Explore Silver Lake Max Depth across LakeQuality
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
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Where this data comes from
67 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_WQX67 samples · 2021–2024
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- In-Vitro Determination of Chlorophyll
- ISU modification of APHA 2130-B
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
Lake size & watershed from HydroLAKES (HydroSHEDS)