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Managing Water to Improve Wetland Functions and Ecosystems

For almost a decade UWRL researchers have been studying the effect of water management and decision making on wetland and riparian areas in Utah. These projects have established and extended systems modeling at and for the Bear River Migratory Bird Refuge, Utah (the Refuge) and helped managers to identify water and vegetation management actions that can improve wetland performance under existing water, vegetation response, budget, staff time, and other constraints.

Citric acid applied to vegetationInvasive wetlands vegetation species, Phragmites australis.

Study Area:

Bear River Migratory Bird Refuge, UT
(Box Elder Co.)
Bear River, UT (Cache County)

Principal Investigators:

David Rosenberg
Karin Kettenring


Al Trout (Friends of Bear River Refuge); iUTAH; Joan Degiorgio (The Nature Conservancy); Bryan Dixon (Bear River Land Conservancy); Bob Fotheringham (Cache County); Toby Hooker (Utah Geologic Survey); Pam Kramer (Division of Wildlife Resources); Bob Barrett,
outline map of Utah showing location of BRMBR

Sharon Vaughn, Howard Browers,
Karl Fleming
, (U.S. Fish and Wildlife Service); Eve Davies (PacifiCorp)


Omar Alminagorta (PhD),
Ayman Alafifi

Project Description

Wetlands, particularly along the Great Salt Lake, provide critical wildlife habitat, resting grounds for migratory birds, and social and economic services including water purification, storm water retention, and recreation for hunters. Wetlands need water, but in Utah and the western U.S., water is often scarce and not available to flood and maintain wetland habitats and functions. Scarce water challenges wetland managers on how to best allocate limited water to and within wetlands to improve ecosystem functions and services. Water allocation decisions are further complicated because responses by bird populations and native plant species are often uncertain.

With these projects, UWRL researcher David Rosenberg has been working toward several wetland management goals at the Bear River Migratory Bird Refuge in Utah, including the following:

  1. Identifying water allocations, infrastructure developments, and vegetation management actions that maximize ecological production subject to budget, water availability, and other constraints.
  2. Classifying satellite images (Landsat) and estimate vegetation cover as well as the extent of flooding in wetland units over ten year period.
  3. Simulating the spread of invasive Phragmites australis as a function of water level changes and the reproduction mechanism (seed or rhizomes).
  4. Populating models and recommending vegetation control actions and water allocations among wetland units that improve wetland habitat.
  5. Providing managers with insights and recommendations to better manage water and vegetation at the Refuge.

Selected Findings

  • Wetland performance decreases markedly with higher invasive vegetation cover. At higher cover levels, systems models that look at only the hydrologic habitat needs of priority species may overestimate performance and mischaracterize the relationship between wetland performance and water availability.
  • Refuge managers can double the area of suitable wetland habitat by more dynamically changing water levels, removing invasive vegetation early in the growing season, and partially controlling Phgragmites in a larger number of wetland units.
  • Other Outcomes

  • A federally-funded National Science Foundation (NSF) effort to extend the model into a Watershed Area of Suitable Habitat (WASH) model for the lower Bear River Basin that identifies numerous near-optimal water allocation strategies to improve wetland and riparian performance.
  • Additional work for the federally funded iUTAH effort to study water user decisions in canals within the context of the larger coupled hydrologic, natural, and built water system
  • A 3-month internship for PhD Student Alafifi at ESRI in Redlands, CA, where he coupled hydrologic and topologic data available in ESRI’s Living Atlas of the World with the WASH model. The resulting maps quantify and show spatial and temporal ecological responses to alterations in flow regimes.

students doing field work field work students doing field work student researchers paddling through wetlands Field sampling

Benefits to Utah

These projecst benefit Utah in several ways. First, they are helping Utah wetland managers better manage and allocate scarce water, personnel, and budget resources to achieve their wetland objectives. Results show how water levels encourage and discourage Phragmites spread and how to manage water to reduce Phragmites spread. Utah environmental managers are better able to allocate scarce water to environmentally important areas across a watershed. These benefits help managers of wetlands and riparian areas promote hunting, birding, and recreation that are vital to the Utah communities that border the Great Salt Lake and the State’s rivers. Finally, the integrated systems modeling, ecology, and remote sensing showcase a new Utah-based approach to environmental management.
These projects seek to enhance current and future decision makers' skills in observation, data synthesis, leadership, and sustainable decision making.

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