Banks Lake
Banks Lake is managed by U.S. Bureau of Reclamation. Published reference elevations are listed below.
Lake Status
We don't have enough recent gauge readings to summarize Banks Lake's status yet. View the water level page for the latest published data.
Watershed drought conditions
Grant County, WA · surrounding county from lake location
Moderate Drought
Moderate drought is affecting the watershed.
Severity
Weekly trend
Stable
Compared with last week
Official drought
Yes
100% of the watershed is currently classified as official drought (D1+).
Expected impacts
- Stream inflows may run below normal
- Lake levels can decline faster between rain events
- Vegetation stress may increase over time
U.S. Drought Monitor · map date Sep 8, 2026. Updated weekly. droughtmonitor.unl.eduView drought map for Grant County, WA
Key Facts
Managing authority
Waterbody / project type
Official purposes
Full pool
Datum
Project / NID identifier
Dam / watershed (NID design values)
Static design values from a confidently matched National Inventory of Dams record — not live gage readings.
- Normal storage
- 586 acre-ft
- Max storage
- 1,200 acre-ft
- Surface area at normal pool
- 586 acres
- Drainage area
- 6 sq mi
- Spillway capacity (design)
- 254 cfs
- Dam structure
- Earth · 15 ft high · completed 1945
- Hazard classification
- Low
National Inventory of Dams · matched record: Jenkins Webley Dam (WA00026)
How this lake is operated
- Documented project purposes (National Inventory of Dams): Irrigation.
Why the level can change
General factors for reservoirs like this
These are common influences for this type of lake. They do not identify the cause of a specific current change unless an operator update confirms it.
Rainfall & inflows
Rain and upstream river inflows can raise reservoir levels, especially after storms.
Downstream releases
When an operator releases water through a dam, reservoir storage can fall and downstream flows can rise.
Flood-risk operations
Some projects store or release water under flood-risk rules when conditions require it.
Water supply
Some reservoirs support municipal, industrial, irrigation, or regional water-supply needs.
Hydropower
Hydropower projects may pass water through turbines when generating electricity.
Seasonal weather
Dry periods, heat, evaporation, and seasonal rainfall patterns can affect storage over weeks and months.
Published reference elevations
- Full pool
- 1570.00 ft
Published reference elevation. Not necessarily a fixed year-round target for every project.
Current data source
Managing authority: U.S. Bureau of Reclamation
Observation source used by Lake Insights: Not published
Who manages the lake and who publishes the reading Lake Insights displays can differ. Lake Insights does not invent a source label from the managing authority alone.
General education
Shared background — not lake-specific facts
Lake Insights aggregates water level information from authoritative public sources such as the U.S. Army Corps of Engineers, NOAA, TVA, Bureau of Reclamation, power utilities, and other official lake operators. We preserve historical observations, calculate trends, and present lake conditions in a consistent format. Lake Insights does not predict future lake levels unless an official forecast has been published by the managing authority.
Common questions about Banks Lake
- Who manages Banks Lake?
- Banks Lake is managed by U.S. Bureau of Reclamation. Lake Insights reports published gauge readings; it does not operate the waterbody.
- What is full pool at Banks Lake?
- The published full-pool elevation for Banks Lake is 1570.00 ft (NGVD29). Full pool is a published reference elevation — not a prediction of today’s level.
- What datum is used for Banks Lake?
- Elevations for Banks Lake are referenced to NGVD29 (MSL).
- What are the documented purposes of Banks Lake?
- Documented purposes for Banks Lake (National Inventory of Dams): Irrigation.