This site has been developed by the Mt. Olympus Community Council to provide all affected property owners real-time updates on efforts to hopefully eliminate and/or minimize effects of the Neff's Creek FEMA alluvial fan flood plain in future years
Millcreek City successfully applied for and received $125,000 in flood plain risk mitigation study grants from FEMA in late 2020, which have been coupled with the city's own $42,112 contributions ($167,112 in total) to help ensure progress on this key community project. Millcreek actively solicited qualified proposals for completing a detailed engineering study that will assess the best methods to appropriately reduce the scope and intensity of the FEMA alluvial fan flood plain affecting the neighborhood. In early 2021, Millcreek selected Bowen Collins Engineering to complete this study. As of late June, 2021 Bowen Collins has completed the initial data collection and field reconnaissance of the area, along with the initial hydrology calculations that quantify the volume and velocity of potential stormwater in the region. The field data research and calculations are currently being used for the key hydraulic models required by FEMA, with the intent to hopefully identify revised but accurate potential risks of flooding in the region. Upon successful completion of this new hydraulic flooding model, Bowen Collins will create a conceptual design and report containing potential locations for numerous types of improved stormwater management infrastructure. Dialogue between Millcreek City, SL County, the State of Utah and FEMA is continually occurring on this important project. Bowen Collins should have its preliminary design for the infrastructure by the end of the summer of 2021. At that point, we can hopefully shift our focus to identifying methods of paying for this infrastructure. The scope of the infrastructure, its associated costs and timing have not been determined yet due to the dynamic nature of the engineering models currently underway. We anticipate having a community meeting to present the results of the Bowen Collins engineering and FEMA's initial response sometime during the fall of 2021. FEMA has still not yet adopted the new flood plain due to it being bundled with other flood plain changes under consideration throughout the Salt Lake Valley, but is requiring Millcreek City to enforce the flood plain restrictions as if the plain were adopted based on the best available engineering information. We anticipate the flood plain will be adopted by FEMA sometime in late 2021. All appeal windows have been exhausted and all submitted appeals were denied by FEMA.
No costs are estimated yet, and cannot be completed until FEMA determines if the city's proposed infrastructure improvements are adequate. No timelines for infrastructure improvements (i.e. debris basin) are determined yet. However, we are cautiously optimistic that the required improvements to reduce a 160 CFS flood risk will be substantially less than FEMA's 300 CFS predicted flood event. The 160 CFS flow rate was identified by CRS Engineers as part of the peer engineering review commissioned by the Mt. Olympus Community Council and affected property owners.
Yes. By federal mandate, Millcreek City must continue to enforce the current building and site restrictions provided in the FEMA Risk Assessment based on the Best Available Engineering Information. That is why we as a community should still be continually focused on the long term goal of reducing the floodplain through improved infrastructure and a potential debris basin. But please remember this issue will not be resolved for between 7 and 10 years on a best case timeline and the final resolution may take longer.
Yes. There is a risk that a significant rainfall in conjunction with a large debris flow can be very hazardous to our community. The US Forest Service and FEMA will be working with Millcreek City and the state of Utah in the coming months to determine if property owners are at greater flooding risk due to last fall's wildfires in Neff's Canyon.
Have a question on the Neffs Creek Alluvial Flood Plain? We'll post answers from residents here as we receive them. Please send your email questions to question@neffscreek.com