Wetland Mapping and Loss in Utah Valley

Wetland mapping informs a wide range of planning efforts by demarcating important habitats and areas where development and wetland conversion may pose greater risks of flooding, higher costs, and potential impacts to downstream communities. The Utah Geological Survey recently mapped over 7000 distinct wetlands (covering 123,000 acres) to update the National Wetland Inventory (NWI) across a rapidly urbanizing area in Utah Valley. We also mapped spring locations and applied supplemental Landscape Position, Landform, Water Flow Path, and Waterbody Type (LLWW) attributes to the wetland mapping to support conservation needs by identifying unique wetland habitats. By comparing archived wetland mapping to landcover datasets, we evaluated wetland losses within Utah Valley following an adapted NWI difference product methodology. Identified losses overwhelmingly resulted from converting wetlands to impervious surfaces and generally coincide with population centers along the north and east shores of Utah Lake. Clustered wetland losses near the cities of Lehi, Saratoga Springs, and Vineyard indicate a general shift of wetland loss westward towards Utah Lake and the Jordan River that mirrors urban population growth and greenfield development of former agricultural lands. Some areas experienced nearly continuous losses over 40 years, indicating increasing urbanization drives ongoing wetland loss in Utah Valley.