SALT LAKE CITY — Gov. Gary Herbert is asking President Barack Obama to declare Utah a major disaster in the wake of last month's storms that produced record-breaking precipitation in Kane and Washington counties.

In letter sent Thursday, Herbert outlined nearly $6 million in damage incurred as a result of the storms, which dropped 16 inches of rainfall and 15.3 inches of snow in the region.

"I have determined that this incident is of such severity and magnitude that effective response is beyond the capabilities of the state and affected local governments and that supplementary federal assistance is necessary," Herbert wrote.

Describing it as a statewide "severe winter event," Herbert said the storm resulted in the activation of the Washington County Emergency Operations Center on Dec. 20 and subsequently a number of resources were deployed.

"The storms and flooding damaged public facilities and private property and threatened the lives and safety of many residents in southwestern Utah," his letter said.

Intense flooding damaged multiple homes, took out bridges, forced evacuations of hundreds and called into question the integrity of two dams. As a result, Herbert said multiple state agencies responded to assist with flood control, assess damage and evaluate dam failure threats, including the Utah Department of Natural Resources, Utah Department of Transportation and Utah National Guard.

He said the most severe impacts were to roads, utility systems, parks and trails.

Per capita costs, when isolated to Washington County, come out at $52.21 as the result of the December storm, and $175.00 per capita in Kane County, according to the governor's letter. Statewide, that figure is at $2.59 per capita.

A statewide report on the water supply outlook for this water year shows that as early January, southwestern Utah had snowpack at 274 percent of average while precipitation in the region was at a whopping 520 percent.

Herbert said the more than ample snowpack, combined with future storms and spring runoff, is likely to result in "debris dams" that redirect stream flows in the Santa Clara and Virgin rivers, elevating threats in the months to come.

A state and regional natural hazard mitigation plan is already under review by Federal Emergency Management Agency officials in Denver.