East Isthmus and Yahara River Watershed Study

Last Updated: 07/31/2020

Project Description

The City of Madison will complete a watershed study in the East Isthmus & Yahara watershed (as shown below). The watershed study will identify causes of existing flooding and then look at potential solutions to try to reduce flooding. The study will use computer models to assist with the evaluations.The City of Madison has hired a consultant, Tetra Tech, Inc to complete the first half of the study where the existing conditions are modeled.

For more information please see the Flash Flooding Story Map.

Map of East Isthmus and Yahara River study area. It extends from east of the capitol to east of the Yahara River.
East Isthmus & Yahara watershed drains primarily to the Yahara River and parts on the far east and west sides of the watershed drain directly to Lake Monona.


The study is beginning Spring 2020 and is expected to take over 12 months. During this time, the City will look at watersheds as a whole to understand the interaction of flash flooding and the increased risk of flooding due to high lake levels.

Public Information Meetings

The first public information meeting for this watershed will occur during the summer of 2020. Information will be posted to this website once a date and location is chosen.

Watershed Study Information

To learn more about flash flooding and why the City is completing a watershed study in this area please visit: Flash Flooding Resilience Story Map

To learn more about lake level flooding, which has impacted this watershed in recent years, please visit: Lake Level flooding Story Map

Listen to a presentation about the City's watershed studies at: Watershed Studies 2019 Audio Presentation.

Report Flooding

If anyone has experienced flooding, and is willing to share with the City, please report it on the City's Report Flooding Portal. Even if a homeowner reported flooding to 2-1-1, FEMA, or a City official, the City needs standardized information to create stormwater models that show existing flooding conditions. The flood data helps the City prioritize different flood projects and future watershed studies.

Additional Information