Cottage Grove Lake water level — Oregon
Cottage Grove Lake in Oregon was last measured at 774.54 ft (datum NGVD29), as of Aug 31, 2026, 1:10 AM (UTC-07:00) (USGS Water Services). Over its recent trend window the level has been falling (−4.3 ft). This reading is provisional and subject to revision.
- % of conservation pool full
- Not reported
- Storage
- Not reported
- Recent trend
- ↓Falling
−4.3 ft over the trend window
Recent trend
Readings this station published between Jun 2, 2026 and Aug 31, 2026 — a 89-day window — downsampled for display.
Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).
Source: USGS site 14153000, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
About this gauge's record
This site's drainage basin covers approximately 104 sq mi of contributing watershed.
The dam behind Cottage Grove Lake
Cottage Grove Lake is held back by Cottage Grove Dam (also recorded as Cottage Grove Lake) , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 103 ft high and running 2,110 ft along its crest , built across COAST FORK WILLAMETTE RIVER in Lane County , near COTTAGE GROVE . It was completed in 1942 , and is owned by USACE - Portland District (a federal owner) , to a design credited to CENWP.
Its recorded primary purpose is flood risk reduction — the pool is drawn down between storms so there is empty space waiting for the next flood, which is why this level can fall in dry weather and climb sharply after rain . It also serves flood risk reduction;other;irrigation;navigation;recreation.
It is founded on rock;soil, with a earth core. Its spillway is ungated: once the pool reaches the crest, water leaves on its own and the operator cannot hold it back. The spillway opening is 264 ft wide.
NID classes it high hazard potential. That describes what a failure would cost downstream — loss of life would be expected — and says nothing about how likely a failure is, or what condition the dam is in.
At its normal pool the reservoir covers about 1,158 acres. NID records a maximum storage of 50,000 acre-ft against a normal storage of 33,000 acre-ft. Its maximum discharge capacity is 40,800 cubic feet per second.
Dam facts: National Inventory of Dams record OR00005 , filed by US Army Corps of Engineers — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)
How Cottage Grove Lake compares nearby
5 of 6 nearby lakes with a current trend are also falling right now.
Nearby lakes
The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.
| Lake | State | Level | Distance |
|---|---|---|---|
| Dorena Lake | OR | 818.32 ft | 11 km |
| Dexter Lake at Dexter | OR | 692.05 ft | 30 km |
| Lookout Point Lake | OR | 842.93 ft | 33 km |
| Fall Creek Lake | OR | 794.86 ft | 35 km |
| Fern Ridge Lake | OR | 368.67 ft | 49 km |
| Hills Creek Lake | OR | 1,460.23 ft | 51 km |
Frequently asked questions
- What is the current water level of Cottage Grove Lake?
- As of Aug 31, 2026, 1:10 AM (UTC-07:00), the pool elevation was 774.54 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
- Is Cottage Grove Lake full right now?
- Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
- Where does this data come from?
- From USGS site 14153000, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in Oregon
See every lake tracked in Oregon, or read the methodology behind these figures.