US Army Corps of Engineers
Rock Island District

Coralville Lake Water Control Plan Update

The current Coralville Water Control Plan was approved in 2001. The Water Control Plans consist of operational parameters defining how, and when, water is stored and released. These include a schedule of releases, conservation pool levels to be maintained during non-flood or drought conditions and downstream water level constraints.

The following key issues inform the primary purpose and need of the Coralville Water Control Plan update:

  1. The Iowa River has experienced a significant increase in the magnitude and frequency of flooding.
  2. Sedimentation within the reservoir has negatively impacted available conservation (water supply)  storage capacity.
  3. Changes in land use and flood risk management infrastructure that effects nature/start of flood impacts (e.g., levees within the City of Coralville, changes to Dubuque Street, etc.).

The purpose of the study is to update the Coralville Water Control Plan to better meet mission objectives based on changes in flood frequencies, land use, and reservoir sedimentation. The District is drafting a feasibility report with an integrated environmental assessment to present a detailed account of the planning, regulatory and environmental considerations resulting in a Recommended Plan.


Current Plan:

Plan Information - Click on the image to view in a larger format.

Coralville Lake Growing Season   Coralville Lake Non-growing Season

Submit Comments Here

As part of the Coralville Lake Water Control Plan Update the Corps of Engineers is asking for your input. Potential topics of discussion (topics provided as example only): - How, and under what conditions, are you impacted by water levels (either flood or drought) along the Iowa River - Concerns related to the effects of water level management actions on recreational use of the reservoir or Iowa River - Environmental concerns, comments or observations related to reservoir operations or Iowa River flows - In regards to the way water is managed at Coralville Lake, recommendations on problems and/or opportunities that should be evaluated as part of the study - Alternatives or actions you believe should be evaluated as part of the study.
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Public Input

Comments about the Coralville Lake Water Control Plan Update may be directed to: or (309) 794-5704. The public comment period has been extended to April 19.

Open House Presentations

Next Open House

When: April 2
Where: High School in Marengo, Iowa (359 East Hilton St.) from 5-7 p.m.
Presentation will begin at: 5:30 p.m. 

Below is a link the presentation used during the meetings as well as a link to the live presentation that was offered on Facebook.