On August 20, 2022, Moab, Utah experienced an unprecedented rainstorm that led to a 100-year flood. The total amount of rainfall attributed to the storm ranged from 1 to 1.5 inches, but close to 1 inch of that amount fell within a 20-minute span. The rain fell southeast of town, draining county and Bureau of Land Management land into Mill Creek, a typically small creek that originates in the nearby La Sal Mountains and meanders through the heart of town.

Moab was unprepared for the amount of destruction and property damage that a storm of this magnitude would cause. In some cases, detention ponds that had been designed to blow out under previously approved plans and flood neighbors did so and in other cases, detention ponds that had been designed to retain stormwater blew out and flooded neighboring properties. A wall of water rushed down Main Street, flooding businesses. Desperate cleanup efforts were launched as Labor Day, the busiest tourism weekend of the year, quickly approached. A lack of integrated land and water use planning was on display.

Though many neighborhoods and businesses were devastated by the flood, others not only survived the storm, but did so without any damage. One of these properties was Moab’s Our Village Community Center. The Center, a local non-profit located on a 5.5 acre farm in the heart of town, runs a pre-school and childcare center as well as many
other community-focused programs.

In the spring of 2020, Annie Thomas, director of the Center, reached out to Jeff Adams, founder and principal of TerraSophia LLC, to address a legacy of stormwater runoff from an adjacent property, a tourism-related business. Drainage from that business’s roofs and parking lot had often flooded the farm buildings now occupied by the Center. The Center had recently completed an extensive remodeling project to bring its facilities up to code to be used as a daycare center and the continued flooding put its mission and goals at risk.

Annie and Jeff developed a project to intercept the sheet flow of stormwater using three basins and swales that intercepted the flow and then poured from one basin into the next. A shallow rolling dip in the Center’s access road allowed overflow from the basins to cross the road and enter another series of basins on the other side, ultimately draining to one of the farm’s fields.

TerraSophia staff led the backhoe and rock work and volunteers transplanted plants salvaged from the local middle school renovation. In all, the project required 3 or 4 days of machine work, 5 or 6 days of rock work, and hours of planting, mulching, and irrigation work. Bee-Inspired gardens and shrubs were also installed to add beauty and privacy.

The Center’s green infrastructure system has served its purpose well, even during the August 20, 2022 flood. Stormwater has been redirected to soak into the Center’s grounds, and most of the donated plants are still thriving.

In the spring of 2022, a second phase of the project installed gentle earthworks around a new heritage tree orchard on the property. Now, when one of the city’s nearby storm ditches overflows and floods the property, the water is directed around the orchard, successfully joining with the initial green infrastructure project to move excess water
offsite. Ongoing maintenance is the new focus; some puddling that has started to occur on the access road will be addressed by the addition of gravel and cobblestones.

One month after the 100-year flood shocked the Town of Moab, there were still large debris piles and layers of sand and mud in some areas. However, the Moab community rallied, and the city and state have worked effectively together to support the citizens and businesses affected by the historic event.

The storm in August 2022 highlighted weak areas in the city’s planning processes and a lack of water and land use integration. The county has since reviewed stormwater management codes, specifically maintenance practices, to ensure that gray and green stormwater infrastructure is appropriately sized, built, and maintained, and that existing
code is enforced.