U.S. Geological Survey field crews are surveying high waters in Iowa to help emergency agencies better respond to future floods.

The USGS crews are establishing high-water marks along the Missouri, Little Sioux and Nishnabotna rivers as part of a Federal Emergency Management Agency mission assignment. High-water marks are visual clues of peak stream height that help verify flood levels recorded by real-time USGS streamgages. The USGS uses these data to help determine the probability of a similar flood event occurring in the future.

“The information USGS crews are collecting for FEMA is valuable for developing flood risk maps and for determining potential impacts of floods on people and infrastructure,” said USGS scientist Paul Rydlund. “Such maps can help managers protect life and property in Iowa.”

The high-water mark data will help FEMA prioritize claims for assistance programs in local communities. They also help develop flood prediction tools for future mitigation efforts.

There are about 200 USGS-operated streamgages in Iowa that measure water levels, streamflow and rainfall.

For more than 125 years, the USGS has monitored flow in selected streams and rivers across the United States. The information is routinely used for water supply and management, monitoring floods and droughts, bridge and road design, determination of flood risk and for many recreational activities.

The USGS Science in Iowa Twitter and Facebook pages are being updated with photos and videos from the field. Access current flood and high flow conditions across the country by visiting the USGS WaterWatch website. Receive instant, customized updates about water conditions in your area via text message or email by signing up for USGS WaterAlert. See where floodwaters go by following a stream trace at Streamer. View water data on your mobile device.