Flooding Hazards

Flooding is the overflow of water onto lands that are normally dry and is the most commonly experienced natural hazard. Desert terrain, snowmelt, and valleys and canyons surrounded by steep mountainous slopes can all contribute to the risk of flooding. When flooding occurs, erosion and considerable deposition of soil and debris can cause additional damage and other hazards. Historically, flooding is the most prevalent, costly, and destructive (on an annual basis) hazard in Utah.

River, Lake, or Sheet Flooding

Overflow of water from excessive river/stream flow, water in lakes, and thin flow across generally flat to gently sloping ground.

Debris Flows

Debris flows, and related sediment flows are fast-moving flow-type landslides composed of a slurry of rock, mud, organic matter, and water that move down drainage-basin channels onto alluvial fans.

Learn More.

Shallow Groundwater

Shallow groundwater can flood basements and other underground facilities, damage buried utility lines, and destabilize excavations.

Dam and Canal Failure

An unintentional release of water due to the failure of a water-retention or conveyance structure (dam or canal) may occur with little warning. The extent of associated flooding depends on reservoir volume and nature of the failure.
Learn More.


A standing (oscillating) wave in a body of water that is at least partially enclosed and can be induced by earthquakes and other energy sources.


A series of waves in the ocean or a lake caused by the displacement of a large volume of water, such as from underwater fault rupture or landsliding into the water.

Costs of Flooding Hazards

2013 flood damage to road near Lees Ferry. Photo courtesy of the National Park Service.

2013 flood damage to road near Lees Ferry. Photo courtesy of the National Park Service.

Flooding hazards have caused significant damage to structures and property, resulting in at least 101 fatalities in Utah since 1847, with 80% of deaths from floods and flash floods, 15% from debris flows, and 5% from dam and water conveyance structure failures. Sixteen major flood events since 1923 have caused over $1.3 trillion in damage, and to date, flooding is Utah’s most costly geologic hazard to the economy.

Related Information:

Geologic Hazards and Insurance – Are You Covered?

Flooding Publications and Maps

Report of Investigation 220

Field Reconnaissance of the Effects of the July 31, 1989 Storm and Flood on Cedar City and the Cedar Canyon Landslide, Iron County, Utah

Report of Investigation 257

Recommended Septic Tank Soil-Absorption-System Densities for the Shallow Unconfined Aquifer in Cache Valley

Special Study 163

Flood Hazard Map – Geologic Hazards of the Tickville Spring Quadrangle, Salt Lake and Utah Counties, Utah

Special Study 162

Flood Hazard Map – Geologic Hazards of the Moab Quadrangle, Grand County, Utah

Special Study 152

Geologic Hazards of the Copperton Quadrangle, Salt Lake County, Utah

View All Hazard Publications

Water Related Articles

Glad You Asked: What Are Ice Caves? Caves 2019
Hole-in-the-Ground, Snake Valley, Millard County, Utah Limestone Geology 2019
Utah’s Early Cretaceous Fossils Provide Critical Data on the Opening of the Atlantic Ocean Dinosaurs 2018
Oil and Gas in the Uinta Basin, Utah –What to Do With the Produced Water Oil and Gas 2018
Monroe’s “Sweet” Groundwater Points to Contamination Source Water 2018
Monitoring Groundwater Response to Large-Scale Juniper Treatments Water 2018
Crystal Geyser, Grand County Water 2018
Does Utah really use more water than any other state? Water 2018
Does Utah Preserve North America’s Oldest Cretaceous Dinosaurs Because of Ancient Salt Deposits? Dinosaurs 2017
2017 Flooding And Landslides In Box Elder County, Utah Hazards 2017
Mapping Wetlands in the Upper Bear River Watershed Wetlands 2017
UGS’s Role in Contributing Water-Quality Data to the National Ground-Water Monitoring Network Groundwater 2017
Wetland Condition in the Weber River Watershed Wetlands 2016
The Salt Crust on Great Salt Lake’s North Arm Great Salt Lake 2016
Skyline 16 Green River Formation Core – World Class Lacustrine Teaching Tool Core Center News 2015
Deep Nitrate in an Alluvial Valley: Potential Mechanisms for Transport Groundwater 2015
When sharks, rays & sawfish ruled Utah’s rivers Fossils 2014
What are keeper potholes & how are they formed? Landforms 2014
Wetland Monitoring in Snake Valley Wetlands 2014
UGS Groundwater & Spring Flow Monitoring in Snake Valley Groundwater 2014
Roosevelt Hot Springs Geothermal Area, Beaver County Water 2014
Using Aquifers for Water Storage in Cache Valley Water 2013
Establishing Baseline Water Quality in the Southeastern Uinta Basin Water 2013
Gandy Warm Springs, Millard County Water 2013
The Goosenecks of the San Juan River, San Juan County Landforms 2013
New UGS study to determine what best to do with water produced from gas fields in the Uinta Basin Gas 2013
Is there winter scuba diving in Utah? Water 2013
Is there coral in Great Salt Lake? Great Salt Lake 2012
Why is Bear Lake so blue? And other commonly asked questions (pdf) Bear Lake 2011
Exploring Utah’s Other Great Lake Water 2011
New Classification Scheme – Great Salt Lake Wetlands Great Salt Lake 2011
What do environmental tracers tell us about groundwater in Snake Valley? Groundwater 2011
How many islands are in Great Salt Lake? Great Salt Lake 2010
Modeling Ground-Water Flow in Cedar Valley Groundwater 2010
Utah Geological Survey’s West Desert Ground-Water Monitoring Network: Progress Report Groundwater 2010
Cascade Falls, Kane County Water 2010
Saline Water Disposal in the Uinta Basin, Utah: Protecting fresh water while allowing for increased hydrocarbon production Hydrocarbons 2010
Why does a river run through it? Water 2009
Unusually High Nitrate Concentrations in Southern Sanpete County’s Ground Water Groundwater 2009
Geothermal Energy Development in Utah Geothermal Energy 2008
Cascade Springs, Wasatch County Water 2008
What are “Potholes” and how are organisms able to live in them? Landforms 2007
Great Salt Lake Trivia Questions Great Salt Lake 2007
Ground-Water Monitoring in Utah’s West Desert Groundwater 2007
Groundwater Water 2006
Proposed Ground-water Withdrawal in Snake Valley Groundwater 2006
New Borehole-Geophysical Logging Program Water 2006
Rozel Point and Spiral Jetty Revisited, Box Elder County Great Salt Lake 2006
Preguntas Comunes Acerca de Gran Lago Salado de Utah ye de Antiguo Lago Boneville (pdf) Great Salt Lake 2005
“Bubblin’ Crude” at Rozel Point, Box Elder County Great Salt Lake 2005

Water Related Articles: 73

External Links