Flooding near the Delicate Arch parking area in Arches National Park should be cured by removal of nonnative tamarisk trees in Salt Wash, according to the Park Service/NPS

Work to improve the Salt Wash drainage near the old Wolfe Ranch in Arches National Park in Utah should begin in January and continue through March now that the plan has been approved by the National Park Service's regional office.

Too much sediment and too many tamarisk trees are behind the frequent flooding of the wash, which empties near the Delicate Arch parking area and access road. All 15 culverts installed under the road at the three wash crossings have filled in with sediment and are non-functional, according to Arches' staff.

The solution adopted by the Park Service is to remove nonnative tamarisk from a 115-acre tract and clean out sediment-clogged drainages.

Tamarisk is a non-native shrub that is extremely invasive in riparian communities, nearly completely replacing native vegetation with impenetrable thickets in many areas. Increased tamarisk cover in the Wolfe Ranch/Delicate Arch Viewpoint areas has clogged wash channels, exacerbated problems of sediment accumulation, and interfered with the natural flow of water.

The project, with work occurring only during the winter months, could take three years to complete. The result would be a significant reduction in the frequency of flood events that lead to closures of the Wolfe Ranch/Delicate Arch Road, the Park Service believes.

Project activities are to take place from January 2018 through March 2018 and from September 2018 through March 2019.