Spring flooding could be problem

ST. GEORGE — No doubt about it, there's going to be a high spring runoff, and Washington County cities are "still very exposed" to potential flood damage, according to Ron Thompson, who manages the county's water conservancy district.

"We don't have a big enough reservoir to catch all the runoff," said Thompson.

Gunlock, Enterprise and Baker Dam reservoirs on the northwest side of the county collect water, but they are not flood-control devices. Quail Creek and Sand Hollow Reservoir on the east side of the county are off-stream reservoirs, which means water must be pumped to their locations for storage.

Snowpack levels above the Virgin River drainage system are about 400 percent of normal, which means there's the potential for even more flood damage along that river this spring.

"If we were to get rain on it today, it would certainly do the same or worse damage in Washington City and Bloomington than the Santa Clara River did (in St. George and Santa Clara)," Thompson added.

Shoring up eroded river banks along the Virgin and Santa Clara rivers is a top priority for area crews, as is removing tons of debris now lodged in several feet of red silt. In fact, the Virgin River bed itself was raised nearly 5 feet by mud dumped near the Man O War bridge in Bloomington.

"This (flood) was the convergence of a lot of bad events," Thompson said during a meeting with state lawmakers on Saturday.

He cited five years of drought, several river channels that were clogged with cottonwood and tamarisk trees, a wildfire that destroyed hundreds of acres of watershed above the Gunlock and Enterprise reservoirs, and a warm rainstorm that melted a heavy snowpack.

"We had a lot of concerns about this kind of event occurring. We wanted to clean the channels, but it seemed like the attitude of the resource agencies was, 'If you touch it, we'll throw you in jail,' " he said.

Much of the flood damage occurred outside the traditional flood plain, undercutting bridges and eating away the abutments holding up the structures. The Santa Clara River flowed out of its normal channel and far out of its designated flood plain by "hundreds or thousands of feet," damaging dozens of homes and swallowing at least 17 more.

"We've got to find a regime that allows us to manage and groom the flood plain," Thompson said. "If we don't, this will occur again."