Finding Your Flood Risk: How High is Your Property?

As the Mississippi River continues to rise, the Corps of Engineers is predicting that much of Terrebonne Parish could be flooded. The flooding will be worse if the Morganza Spillway is opened, but there is likely to be flooding even if it stays closed. Officials are urging everyone to prepare for rising waters. One of the most important things to find out is the elevation of your home, apartment, or business. Flood waters are predicted to reach up to five feet above sea level across the parish. Anyone who lives or owns property below five feet is being encouraged to prepare for rising water.

How do you find your elevation? The easiest way to do so is to go to the Wind Speed and Elevation Map webpage maintained by the LSU AgCenter. When you click on this page, you will see a map of Louisiana, showing different wind speed predictions for hurricanes. Since wind speed not applicable in this situation, you can click the Basic Wind Speed button on the left side of the page to "Off". The map will now show a basic, zoomable road map of the state. Buttons above the map let you switch to a satellite, or "aerial" view, or a hybrid road/aerial view.

While you can simply click on the approximate location of your property, a more accurate method is to enter your address into the search box at the top of your page. Enter the street, city, state, and zip code; each separated by a comma. If the page recognizes your address, the elevation at that point will appear on the left side of the page. The lower the elevation of your property, the more critical it is to prepare for flooding.

You may also encounter other flood maps online. FEMA produces detailed flood maps used to map flood risks for particular locations. The older style of flood maps, called a Flood Insurance Rate Map, or FIRM, were originally print maps, although they can often be found online as zoomable, scanned images. The newer style of FEMA flood map is called a Digital Flood Insurance Rate Map, or DFIRM. FIRM's and DFIRM's are excellent for finding detailed flood risk information, but understanding them requires a good deal of background information. The LSU AgCenter has an excellent interactive flood mapping website, but people using it should be sure they understand how to read FIRM and DFIRM maps. The site links to important special instructions for using these maps when flood waters are rising. Also, this site seems to work in Internet Explorer, but not Firefox. LSU AgCenter's blog also has instructions for using both of its mapping services.

If you have any difficulty finding the elevation for your property, call or visit our reference desk at the Main Library. Our friendly reference staff can be reached at (985) 876-5861, option 2.

Keeping An Eye on the Mighty Mississippi

If you have been following the news, you know that the Mississippi River is higher than it has been in decades, due to heavy rain and snowmelt in the upper reaches of its watershed. This has already caused flooding along the upper Mississippi and its tributaries. As all this water flows downstream toward Louisiana, the downriver portions are getting more and more swollen. The river is expected to crest in Baton Rouge on May 22, and in New Orleans on May 23.

To prevent the river from breaking or spilling over levees, the Army Corps of Engineers has diverted some of the flow into other areas. The Bonnet Carré Spillway, just upriver from New Orleans, was opened on Monday, May 9, to divert water from the Mississippi River into Lake Pontchartrain. Also on Monday, the Corps of Engineers put in a request to open the Morganza Spillway, upriver of Baton Rouge. This would divert water from the Mississippi into the Atchafalaya River, resulting in widespread flooding along the Atchafalaya's course. The Corps has released an inundation map showing expected flood levels in this area. As of Monday evening, officials have not decided whether to open the Morganza, but if they do, it could happen as early as Thursday, May 12.

If it is opened, the worst flooding is expected to occur in parishes around the spillway, especially West Feliciana and St. Martin. However, flood waters of up to five feet are expected across much of Terrebonne Parish. This is serious, but not as serious as it sounds, because most of the land area of Terrebonne Parish consists of low-lying, unpopulated wetlands. Most populated areas are higher, and should not see this much flooding, if any. Also, the water will rise slowly, over a span of several days. Still, officials are urging parish residents to prepare for flooding, especially in communities in the western part of the parish, such as Gibson, Donner, and Chacahoula.

Parish residents are strongly encouraged to start planning now, in case they need to evacuate or take measures to protect their property. All residents should check to see if their houses and businesses are less than five feet above sea level. Anyone with property below this level should take measures to protect it. The Houma Courier reports that residents can get sandbags at the following locations:

• Gibson Fire, 110 Merry Moss St.
• East Gibson Fire, 5218 N. Bayou Black Drive.
• Devon Keller Memorial Gym, 5575 Bayou Black Drive.
• Donner-Chacahoula Fire, 1805 La. 20.
• Bayou Black Fire, 2820 Savanne Road.
• Schriever Fire, 1529 W. Park Ave.

All residents, even those who live above five feet, should prepare for possible disruptions associated with flooding. The links below have more information about following and preparing for this situation. Please check the Terrebonne Parish Library's website, and this blog, for more information. As we receive updates, we will post them here.

Local Resources

• Officials: Plan now for River Flooding
  
• Get ready now for high water
• Unleashing the Flood
  
• Flooding could reach 5 feet
• Terrebonne braces for flooding
• Corps opens gates at Bonnet Carre spillway
• Terrebonne Parish Office of Homeland Security and Emergency Preparedness / Public Safety
• FEMA Flood Maps for Terrebonne Parish

State Resources

• 2011 Spring Flood Alert! (See this page for links to determine elevation and flood risk where you live)
• State Library of Louisiana > Flood Resources
• Governor's Office of Homeland Security & Emergency Preparedness
• Louisiana OLD RIVER CONTROL STRUCTURE and Mississippi river flood protection

Federal Resources

• National Weather Service, Lower Mississippi River Forecast Center
• Army Corps of Engineers, New Orleans District
• FEMA
• FloodSmart.gov
  

LSU AgCenter: Online Tools for Flood, Windspeed

The kind and dilligent folks at the LSU AgCenter have clued us in to some great online tools for getting a good idea of what storm surge and windspeed might look like during the next hurricane.

Just enter your address and city and see what mother nature could do if she were in the mood.

Windspeed & Ground Elevation--LSU AgCenter's Windspeed & Elevation Map

Flood Maps--Louisiana Flood Map Portal

LA Mapping Project--Terrebonne Parish

The Next Storm Surge: How High's the Water, Mama?

The LSU AgCenter, Louisiana Sea Grant and Bayou Interfaith Shared Community Organizing will be presenting "The Next Storm Surge" at the Terrebonne Parish Main Library on Monday, August 17 from 5pm-8pm in the large meeting room.

The presentation will include:

> Historical Hurricane Impacts on Coastal Louisiana; Factors Influencing Hurricane Storm Surge in Coastal Louisiana

> “What If” Hurricane Storm Surge Impacts on Terrebonne and Lafourche Parishes

> New Flood Zones: What They Mean and How They Will Impact You

This program was hosted at the Main Library last year and, since then, storm surge and wind-speed models have been updated, taking the impact of Hurricanes Gustav and Ike into account.

Lsu AgCenter staff will be available to help those in attendance access windspeed, ground level and storm surge models available online through the LSU AgCenter.

Attendance is free.

For information on other locations where this meeting will be held, follow this link:

Storm Surge Meetings, August 2009