HNA Summary Report
Executive Summary

This summary report describes the first Habitat Needs Assessment (HNA), in support of the Upper Mississippi River System (UMRS), Environmental Management Program (EMP). The EMP Habitat Needs Assessment was designed to help guide future Habitat Rehabilitation and Enhancement Projects on the UMRS. To identify habitat needs, historical, existing, forecast, and desired future conditions were compared. Issues of scale are important in this regard because ecological processes and needs vary at the system, reach, and pool levels. In addition, a wide variety of habitat characteristics must be addressed including habitat fragmentation, connectivity, and diversity. To accomplish this assessment, a GIS tool and a new floodplain vegetation successional model were developed. These tools allow geomorphic and land cover characteristics to be translated into the potential habitat areas for species to occur.

The Results   
Over time, the landscape, land use, and hydrology of the Upper Mississippi River and its basin have changed. Much of the grasslands, wetlands, and forests have been converted to agricultural use, which now occupies 50 percent of the floodplain. Impoundment, channelization, and levee construction have altered the hydrologic regime and sedimentation patterns, resulting in loss of backwaters, islands, and secondary channels. While future changes in broad geomorphic features are expected to be relatively small, habitat degradation is expected to continue. There is a broadly recognized need among resource managers and scientists for improved habitat quality, increased habitat diversity, and a closer approximation of pre-development hydrologic regime.

The Habitat Needs Assessment identified clear differences in habitat types and conditions among river reaches. Those differences are largely related to the amount and distribution of public land, the degree of floodplain development, the geomorphic form of the river, and the effects of impoundment for Executive Summary navigation. The differences also suggest that habitat needs and restoration objectives will vary by river reach and pool.

The Habitat Needs Assessment yielded gross quantitative and qualitative estimates of habitat needs both system-wide and within river reaches. These estimates provide the first approximation of a set of system-wide objectives for Habitat Rehabilitation and Enhancement Projects. While they do not offer quantitatively precise goals, they will help focus future planning on the most important geomorphic processes both system-wide and in specific river reaches. However, perhaps the greatest contribution this first Habitat Needs Assessment has made is the development of new and improved tools for future planning for Habitat Rehabilitation and Enhancement Projects. In particular, the GIS Query tool will help evaluate the potential distribution of species and habitat area types throughout the UMRS. While the results of the Habitat Needs Assessment are not a substitute for the more detailed and spatially explicit planning that will be done at the pool scale, it has provided new tools for that planning.

The Future   
This is the first Habitat Needs Assessment undertaken as part of the Environmental Management Program and it is anticipated to be updated on a regular basis. Future assessments will benefit from additional spatial data about the river system, improved ecological understanding, improved GIS and modeling tools, and additional public input.

 Limitations of the Initial HNA

• The Habitat Needs Assessment simplifies access to, analysis of, and graphic display of vast amounts of data, but the results still require careful interpretation by individuals familiar with UMRS resources.
• Because there were schedule and cost constraints, this study relied heavily on existing studies and it is limited by the quality and uniformity of data contained within those studies. The HNA will continually evolve as new information is acquired and it will be periodically updated in accordance with the Water Resources Development Act of 1999. Its value will continue to increase as new and more comprehensive data is incorporated during subsequent updates.
• The HNA was limited to the use of existing system-wide data. System-wide habitat models used relatively uniform low resolution land cover data and are therefore very general, even in data rich areas.
• The HNA provides an additional tool to help determine how Habitat Rehabilitation and Enhancement Projects are identified and selected, but it does not replace the project planning process.