Quail Creek Reservoir

View of the back of the secondary dike as it exists today. slgwv (Atlas Obscura User)

Looking east across Quail Creek Reservoir. slgwv (Atlas Obscura User)

Telephoto view of the back of the main dam. slgwv (Atlas Obscura User)

Looking south across Quail Creek Reservoir from 5300 West road in October 2022. The main dam is at the low point on the ridge where the far shoreline is, just right of center. slgwv (Atlas Obscura User)

Flood-scoured channel downstream. slgwv (Atlas Obscura User)

Washed-out bridge on Utah State Route 9. The main channel of the Virgin River is at the right. slgwv (Atlas Obscura User)

Washed-out bridge on Utah State Route 9. slgwv (Atlas Obscura User)

The remaining reservoir behind the main dam in January 1989. slgwv (Atlas Obscura User)

The remaining reservoir behind the main dam (behind the ridge in the middle distance) in January 1989. slgwv (Atlas Obscura User)

The breached dike, ca. January 1989. slgwv (Atlas Obscura User)

Looking along the breached dike, ca. January 1989. slgwv (Atlas Obscura User)

The rebuilt secondary dike as it appears today. slgwv (Atlas Obscura User)

Partly drained reservoir floor behind the breached dike. slgwv (Atlas Obscura User)

Close-up of the secondary dike from the ridge to the west. slgwv (Atlas Obscura User)

Quail Creek Reservoir as seen from the high point on the ridge to the west. The secondary dike is at the right; the main dam is at the end of the prominent inlet just right of center. slgwv (Atlas Obscura User)

Quail Creek Reservoir, on Quail Creek in southern Utah, looks to be a typical small storage reservoir in the arid West, complete with marinas, bait shops, and boat-launch ramps. It has an unusual history, however: this reservoir caused a catastrophe, which nonetheless could have been much worse, in the late 1980s while it was being filled completely.

The reservoir is created by a main dam, some 200 feet high, on Quail Creek. However, a secondary dike, shorter in height (78 feet) but much longer (1,980 feet) than the main dam, was also needed to prevent the reservoir from overtopping a saddle to the southwest. The foundation of this dike turned out to be seriously flawed, and considerable leakage kept occurring as the reservoir was being filled. Ongoing efforts to plug the leakage with injected grout seemed to be successful, however, and so filling continued. However, a catastrophic leak erupted on December 31st, 1988, and when efforts to staunch it failed, evacuation orders were issued for all downstream areas. Finally, at 12:30 a.m. on New Year’s Day 1989 the dike collapsed completely, and the resulting outflow quickly drained the upper part of the reservoir. Fortunately, due to the evacuation warning the flood caused no loss of life downstream, but there was still some $12 million of property damage (equivalent to some $29 million in 2023).

In 1990, the dike was rebuilt with a considerably better foundation, and in the 30-odd years since there have been no further problems.

Know Before You Go

Road 5300 West, which runs along the northwest side of Quail Creek Reservoir, has a junction with Utah State Route 9 about 2.6 miles east of the intersection of SR-9 with Interstate 15. In less than a mile there is an excellent view of the secondary dike off to the right (east).