Porch notes
- On May 1-2, 2010, Nashville International Airport recorded 13.57 inches of rain, more than double the previous two-day record of 6.68 inches, according to the National Weather Service.
- Structures in a Special Flood Hazard Area have a 26 percent chance of flooding during a standard 30-year mortgage, Metro Water Services says, and properties outside it are not guaranteed to be safe.
- Standard homeowners insurance does not cover flooding, and flood policies usually have a 30-day waiting period.
Most people who move to Nashville have heard of the May 2010 flood. Fewer realize how much of the damage came not from the Cumberland River but from the creeks that wind through residential neighborhoods. If you are buying a home, flood risk deserves a careful look, whether or not the house is near the river.
What happened in May 2010
The National Weather Service office in Nashville, whose records go back to the early 1870s, documented a series of records over two days.
| Measure | Record |
|---|---|
| Rain on Saturday, May 1 | 6.32 inches, then the second-highest day ever |
| Rain on Sunday, May 2 | 7.25 inches, the wettest calendar day on record |
| Two-day total, May 1-2 | 13.57 inches; the old record was 6.68 inches |
| May 2010 as a whole | 16.43 inches, the wettest month on record |
| Cumberland River at Nashville | Crested at 52.55 feet on May 3; the record of 56.20 feet dates from 1927, before dams controlled the river |
The storm killed 18 people in Middle Tennessee, and the Weather Service puts property damage above two billion dollars.
The creeks
In Nashville, many creeks rose higher than in the 1979 flood. The Weather Service lists several:
- Richland Creek crested at 19.99 feet, almost five feet above the 1979 level.
- Mill Creek at the Antioch gauge reached 26.10 feet, above its 1979 record of 23.78 feet.
- Mill Creek at Woodbine set a record of 21.37 feet.
- Whites Creek in Bordeaux crested at 25.82 feet, more than six feet above its previous record.
- Browns Creek at the State Fairgrounds rose to 13.44 feet, five feet above its previous record.
After the flood, Metro worked with the U.S. Geological Survey to add twelve river gauges in Davidson County, and the Corps of Engineers built detailed models of the creek basins to map what floods at what level. Warnings today are better than in 2010. The lesson for buyers is that a quiet creek at the bottom of the street can be the bigger risk.
Reading the flood maps
Metro Water Services explains that Nashville takes part in the National Flood Insurance Program and uses FEMA’s Flood Insurance Rate Maps. Those maps show Special Flood Hazard Areas, the land with a 1 percent chance of flooding in any year. Metro puts the risk in more useful terms: a structure in that area has a 26 percent chance of flooding over the life of a standard 30-year mortgage.
Metro is just as clear that land outside the mapped area is not guaranteed to stay dry. All streams in the county are subject to flooding, and backwater flooding can be significant.
How to check an address
- Use Metro’s Parcel Viewer, which shows regulated floodplains and related elevation certificates.
- Search FEMA’s flood map service online.
- Call Metro Water Services’ Development Services Division, which on request provides the flood zone, map panel, base flood elevation, floodway status and copies of elevation certificates.
Insurance
Metro Water Services spells it out: flooding is not covered by a standard homeowners policy. Flood insurance is available to homeowners, condo owners and renters, and renters are encouraged to insure their contents. There is generally a 30-day waiting period before coverage starts, so a policy bought when rain is in the forecast will not help. FEMA’s online quoting tool gives an estimate based on the address and basic features of the home.
Tip: Ask your lender early whether it will require flood insurance, and get a quote before you commit. The premium belongs in your monthly budget alongside the mortgage and taxes.
What the seller has to tell you
Tennessee’s residential disclosure law, Tenn. Code Ann. 66-5-202, requires sellers to give buyers a property disclosure statement. In a 2006 resolution, the Metro Council noted that the disclosure statement already required sellers to say whether there are flooding problems on the property, along with hazards such as asbestos and lead-based paint. The council asked state lawmakers to go further and cover flooding in the surrounding area. Read the disclosure carefully, ask direct follow-up questions and look for water stains in basements and crawl spaces.
Building or adding in a floodplain
Metro’s stormwater rules are strict for good reason:
- All development in a Special Flood Hazard Area needs local permits, not only new buildings.
- New homes in the floodplain must have the lowest finished floor four feet above the 1 percent annual chance flood elevation.
- Fill placed in the floodplain must be offset with an equal volume of soil removed.
- Development in the floodway is prohibited, with few exceptions.
- A grading permit is needed for land disturbance over 10,000 square feet.
If you are buying a lot to build on, or a house you plan to expand, find out early whether these rules apply.
If disaster damages a home you own
The Assessor of Property notes that state law lets the value be adjusted if a building is substantially damaged by fire, flood, wind or another disaster between January 1 and September 1, and asks owners to contact the office with written repair estimates. More on taxes is in Davidson County Property Taxes: How Your Nashville Tax Bill Is Figured.