Officials Encourage Preparation for Groundwater Flooding Hazards
SALT LAKE CITY (May 3, 2023) – Record snowpack across the state has increased the potential for groundwater flooding, landslides and debris flows in some areas. Many areas statewide have already experienced flooding and landslides. These hazards will increase as temperatures warm up.
Flooding can occur from surface water from rivers and streams or shallow groundwater. Shallow groundwater occurs when the water table is within 20 feet of the land surface. During persistent heavy rains, snowmelt, or surface flooding, water moves downward through the soil to the groundwater table causing water levels to rise, creating problems for building foundations and basement flooding. This spring, areas not typically prone to shallow groundwater may temporarily experience increased levels.
Utah Geological Survey (UGS) hazards geologists are working on mapping shallow groundwater hazards in the state to determine the likelihood of flooding in cities and neighborhoods.
“Geologists have mapped the west side of the Salt Lake Valley from Kennecott to Eagle Mountain, areas in Washington County and the Moab area. We are working on updating more areas along the Wasatch Front and anticipate completing this by June,” said UGS Senior Geologist Jessica Castleton. “These maps are intended to inform residents of the likelihood of shallow groundwater in their area. The information can also be used to take steps to safeguard properties during wet periods.”
Homeowners can also report shallow groundwater flooding to UGS to be compiled into a public database for future hazard mapping reference.
UGS and the Division of Emergency Management (DEM) are working closely with other local, state and federal agencies to help educate people about the multiple flood hazards created by the record snowpack, including shallow groundwater, and how to prepare. DEM strongly encourages people to consider flood insurance as part of that preparation. However, groundwater flooding is not covered by the National Flood Insurance Program (NFIP).
“The NFIP defines flood as an excess of water on land that is normally dry, affecting two or more acres of land or two or more properties, unusual and rapid accumulation or runoff of surface waters from any source,” says Tracie Harrison, DEM Flood Program Manager. “ Individuals should contact their insurance agent to see if the private insurance markets may have policies specific for groundwater flooding.”
A federal disaster declaration may provide some assistance, but to qualify, the state must have enough damage to meet and/or exceed the damage threshold set by FEMA. The statewide threshold amount for the 2023 fiscal year is $5.7 million. If a singular disaster event produces that much damage, the state can request that a declaration be made on the federal level.
“Just because a request is made does not mean it will automatically be approved. If a federal declaration is granted, it can open up various federal programs such as Public Assistance and Individual Assistance, and SBA loans,” says Kathy Holder, DEM State Hazard Mitigation Officer. “The best option is to take steps to prevent the damage from occurring in the first place because even if Utah gets a federal declaration, we may not receive Individual Assistance for victims. There are other qualifiers for the Individual Assistance program. Individual assistance can provide as much as $37,900, but typical grants are usually a fraction of that amount, averaging $8,000 or less.”
UGS and DEM staff advise residents to take precautions to protect their homes and property from groundwater flooding. Homeowners should improve outside surface drainage, repair foundation cracks, ensure that their sump pumps work correctly and consider installing additional groundwater drainage systems around their homes. They should also check with their insurance providers to see if they are covered for flooding caused by shallow groundwater.
For additional statewide flood information, at floods.utah.gov.