UPDATE | February 2023:Harpeth Conservancy raised concerns about flood safety issues to planning staff and the Developers. In response, the Developers modified their flood study and proposed a potential solution to some of the safety concerns addressed below. To help prevent residents from being trapped on Coley Davis Road during flood events, the Developers propose elevating Coley Davis Road above the 500-year floodplain and the 2010 flood levels. Harpeth Conservancy will continue to monitor the Developer’s proposal to ensure the project does not negatively impact residential flood safety.
Harpeth Conservancy has been involved in flood recovery and floodplain management policy for many years. Our organization is a coalition member of Flood Ready TN. This coalition of elected officials, homeowners, small business owners, faith leaders, and community members across the state are dedicated to making Tennessee resilient against frequent flooding. Flood safety is of critical importance for developments along waterways especially during rezoning, plan amendments, and related land use decisions.
Metro has recently contracted with the Army Corp of Engineers to update river flow and rainfall statistics across Davidson County as part of an effort to incorporate the impact of climate change into flood risk modeling. Over the past several decades, the incidence of major rainfall events in the Middle Tennessee region have increased. Nowhere is that more clear than in Bellevue, where the 2021 flood was second in magnitude to only the 2010 flood a mere decade prior. The Army Corps’ work will be very valuable in evaluating any proposed changes to current zoning, transect policy, other aspects of Nashville Next and subdivision regulations. Nowhere will this effort be more clear than on the proposed development property.
Public Safety during Flooding is a Significant Concern with this Proposed Rezoning for an Apartment Complex:
The National Weather service, Turn Around, Don’t Drown campaign is very clear about floodwater risks. Six inches of water will reach the bottom of most passenger cars and cause loss of control and possibly stalling. A foot of water will float most vehicles. Two feet of moving water can carry away most vehicles including SUVs and pick-up trucks.
The cost of emergency response is not fully recovered from disasters and puts emergency personnel at risk as well as the risks the loss of or damage to equipment.During the March 28, 2021 flood Metro lost a million dollar plus fire truck when it was responding to a flood call. The flood waters on Old Harding from the Harpeth were deep enough that the fire truck lost the ability to control the truck and the team had to abandon it.
Flood fatalities are the second leading weather-related cause of death after heat. Flood fatalities are predominantly from people driving into floodwaters, especially at night. Ariza Bellevue developers have stated that “many residents in neighborhoods across the Nashville region would need to shelter in place” and that the Ariza buildings “will remain outside of the flood zone to provide refuge for our residents.” This response misses the fundamental issue with public safety during flooding- of all flood fatalities over the past 11 years (2010-2022), the largest activity victims were performing was “driving.”
During major flood events, Ariza Bellevue would leave 417 households surrounded by floodwaters. This increases the likelihood of people driving through floodwaters, straining emergency services and creating critical public safety risks.
Transportation Access to this Property Would Also Be Compromised by Major Flooding
The proposed site of this project is compromised by floodwaters not just at the close proximity to the proposed development but further away as well! The map below indicate four areas where flood waters inundate roads that hamper both access to the property directly as well as emergency access and response. The maps and data of depth of water on Coley Davis and Morton Mill are provided by Barry Moran, Hydraulic Engineer, for the Nashville District of the Army Corp. He led the project for Metro to update the current adopted floodplain maps in this area after the 2010 Flood. This information is from the Metro GIS maps.
This map was prepared by Harpeth Conservancy to show the 4 areas constrained by floodwaters.
The geographic constraints of the subject property make anticipated suburban development on the site challenging without significant alterations.
Development of the property as proposed would not create a level of connectivity sufficient to meet T3 standards. T3-NE Connectivity guidelines call for “moderate” vehicular connectivity to “provide residents with multiple route options to destinations.” Currently, the Morton Mill property is accessible solely by a driveway including an unguarded crossing over the CSX right-of-way. The owner’s development plans for the site call for a single bridge to be constructed over the Harpeth River to the north, connecting the property to Coley Davis Road. This bridge access would be the sole means of ingress and egress for residents. (A grade crossing on Morton Mill Road would remain for emergency vehicles only.)
The road the Morton Mill property owners intend to connect via bridge, Coley Davis Road, terminates at the Harpeth River to the west. East of the proposed Morton Mill property bridge, Coley Davis has been submerged in as much as three feet of water in recent Nashville flood events. In those same flood events, Morton Mill Road, to be used for emergency access only, has also been submerged by floodwaters. Connectivity to the property, already low, could be fully eliminated during floods.