Technical Reports & Maps




Proposed Surface Water Source Protection Areas

Source Water Protection 2020

Rathbun Lake Water Quality Summary 2008 - 2019
(The US Army Corps of Engineers (USACE) Water Quality Program collects monthly water samples at Rathbun Lake* April through September. Prior years inflow monitoring results can be found at RLWA.ORG. These figures present data collected between 2009-2018 from inflow streams (RA-12, RA-15, RA-43), lake sites (RA-3, RA-7, RA-8, RA-25), and the outflow (RA-28) at the dam. Thirty-four chemical, physical, and biological parameters are measured to evaluate water quality. USACE use this data to describe conditions and changes from the inflows, lake, and outflow focusing on eutrophication, nutrients, sediment, herbicides, metals, and contaminants.)

2017 Monitoring Summary 
Iowa Department of Natural Resources
Prepared by Jen Kurth

Rathbun Lake and Watershed 2015 Monitoring Summary
Iowa Department of Natural Resources
Leading Iowans in Caring For Our Natural Resources

Rathbun Lake and Watershed 2014 Monitoring Summary
Prepared by
Michelle Balmer
Lake Monitoring Coordinator
Iowa Department of Natural Resources

Stressor Identification for Dick Creek
Wayne County, Iowa
Prepared by: Jason Palmer, Iowa Department of Natural Resources
Watershed Improvement Section &
Watershed Monitoring and Assessment Section 2012

 2011 Water Quality Monitoring Data
Submitted by Iowa State University Department of Ecology,
Evolution, and Organismal Biology


2010 Water Quality Monitoring Data
Submitted by Iowa State University Department of Ecology,
Evolution, and Organismal Biology

Priority Land Modeling Map
The Rathbun Lake Watershed is divided into 61 subwatersheds. GIS technology identifies land – priority land – within these subwatersheds that is most likely to deliver sediment and phosphorus to Rathbun Lake. 
Work is underway with landowners in 45 of the 61 targeted sub-watersheds.
· Assistance has been provided to close to 600 landowners.
· Practices have been planned and applied for 25,000 acres.
· Annual sediment delivery to the lake has been reduced by 46,000 tons.
· Annual phosphorus delivery to the lake has been reduced by 199,000 pounds.
· More than 1,500 acres of wetland, riparian, and shoreline areas have been restored.
· Monitoring indicates that water quality in the lake and tributaries has been relatively stable.
· Sixty landowners have been recognized for their efforts as Rathbun Lake Protectors


To assess the benefits of the implemented conservation practices, water quality monitoring is carried out at specific sites throughout the watershed.


Brush Creek Sub-Watershed - Priority Land Work


Maps of installed BMPs on the land of Rathbun Lake Protectors
Ron and Darla Main - 2008 Rathbun Lake Protectors - Wayne County
Jim and Barb Cory - 2008 Rathbun Lake Protectors - Wayne County
Mike and Tracy Shay - 2008 Rathbun Lake Protectors - Clarke County
Dick and Connie Hines - 2008 Rathbun Lake Protectors - Decatur County
Chuck and Connie Moore - 2008 Rathbun Lake Protectors - Appanoose County
Swartz Family - 2008 Rathbun Lake Protectors - Lucas County
Dwaine and Twyla - 2008 Rathbun Lake Protectors - Lucas County