Rivers and Streams
Hoover Creek, a tributary of the West Branch of Wapsinonoc Creek, runs through Herbert Hoover National Historic Site. The National Park Service hopes better watershed planning will address flooding, erosion, and water quality problems that threaten the landscape commemorating the 31st President of the United States.
A Disturbed Watershed
Hoover Creek drains about 1,700 acres of agricultural, rural residential, and urban land. It also drains the hard surfaces within the National Historic Site. Settlers and immigrants in the 1800s who removed trees from creeks and swamps and started farming the prairie altered the local hydrology from a ground water based system to a surface water system. Continued development of the watershed upstream affects both drainage and water quality.
Today's creek flows faster and cuts straighter and deeper than the bucolic stream of the past. Instead of seeping slowly underground through the native prairie soil, rain and runoff from farms and pavement run right into the creek channel and carves an ugly scar into the landscape. Periods of intense rainfall cause flash floods that threaten to undermine and inundate the Herbert Hoover Birthplace Cottage, the Presidential Library and Museum, and other important or irreplaceable buildings.
Agricultural land in the watershed is tiled (drained with underground pipes) and development has pressed close to the creek banks during the last century. This encourages the creek to flash flood in the park during peak flows. Further development on the west side of the city may result in more frequent flood occurrences than when the land was in agricultural use.
Data and Reports
The U.S. Geological Survey (USGS) supports a real-time data stage gage in Herbert Hoover National Historical Site. It provides data on current and historical conditions (discharge, temperature, and rainfall) for Hoover Creek. The USGS prepared a flood map and frequency report flood map and frequency report (PDF file, 313 KB).
Concerns about water quality in Hoover Creek center around siltation from soil erosion, and levels of nitrate and coliform bacteria. Coliform bacteria levels rise above safe levels as the stream enters the park, but fall to much lower levels by the time the stream leaves the park.
Data and Reports
Volunteers sample water quality at Hoover Creek in Herbert Hoover National Historic Site. The sample site is number 916066 in the IOWATER database. The Iowa Department of Natural Resources (DNR) reported on trends in water quality on Hoover Creek (PDF file, 228 KB).
Scientific studies of the creek's hydrology and water quality suggest solutions for restoring its health. If you are interested in improving the creek and protecting the park from floods, soil erosion, and water pollution, you can learn more from the planning documents listed below or by contacting us with your support.
The Hoover Creek Stream Management Plan and Environmental Impact Statement, 2006 (PDF file, 8,384 KB) examines five management alternatives for mitigating flooding and erosion of Hoover Creek that threaten both the National Historic Site and the Presidential Library and Museum. The environmentally preferred alternative protects the National Historic Site resources from the 50-year recurrence flood.
Engineering Report for the Stream Management Plan (PDF, 2.0 MB) analyzes the instabilities in Hoover Creek that threaten park resources. The solutions considered in the Stream Management Plan were based on this report.
Working Drawing of Hoover Creek Restoration Design Elements (PDF file, 17.0 KB): a map illustrating the proposed improvements to Hoover Creek.
Design Proposal: Storm Water Management for Hoover Creek Watershed (PDF file, 983 KB), prepared by engineering students at the University of Iowa in 2010, will help the park apply for funding to reduce the amount of runoff into the creek.
Did You Know?
General Land Office surveyors who first came to Iowa commented that the territory was fit only for waterfowl. Eighty-five percent of Iowa used to be soggy tallgrass prairie. More...