↓
 

Huntsville Land Surveying

Land Surveying in Huntsville, Madison County, Alabama

Huntsville Land Surveying
  • Home
  • ALTA Survey
  • Boundary Surveying
  • Construction Survey
  • Drone LiDAR Mapping
  • Elevation Certificate
  • Lot Survey
  • Land Surveying
  • Topographic Survey | Topo Survey
    • Contour Lines and Finding Profile in a Topographic Map
  • Contact Us
Home - Page 5 << 1 2 3 4 5 6 >>

Post navigation

← Older posts
Newer posts →

How To Find Your Home On FEMA’s Flood Insurance Rate Maps

Huntsville Land Surveying Posted on October 18, 2010 by HunstvillePLSNovember 22, 2017

Flooding Map: Is it Important?

FEMA's Flood Insurance Rate Maps

FEMA’s Flood Insurance Rate Maps

FEMA’s Flood Insurance Rate Maps (FIRMs) are issued after a flood risk assessment has been completed or updated for a community.  This study is known as a Flood Insurance Study.  The FIRM shows the Base Flood Elevations (BFEs) and insurance risk zones in addition to floodplain boundaries.  The FIRM may also show a delineation of the regulatory floodway.

Once the “insurance risk zone”  (commonly referred to as the flood zone) is determined, actuarial rates, based on these risk zones, are then applied for newly constructed, substantially approved, and substantially damaged buildings.  FEMA uses these rates to determine the insurance rate you will pay for flood insurance.

Viewing a Flooding Map Online

To view these maps online, go to FEMA’s Map Service Center and enter your address (hi-lited area shown here) to search for your home.  This will allow you to then select the flooding map that covers your area.  The Flooding Maps are somewhat cumbersome to use online. I suggest going through the tutorial on the bottom right of the address search page in order to learn how to maneuver around in this GIS map.

 

Flooding Map on Huntsville, AL

If you are located in the City of Huntsville, you might also check out the Huntsville Interactive GIS maps for more information and a little easier interface. Check the FEMA Flood Insurance Rate Map box on the left to view the flood zones on this map.

Call Huntsville Land Surveying at (256) 585-6002 if you need help with this process or if you discover you are near a flood zone and need an elevation survey completed.  We are here to help you minimize your flooding risk.

Posted in blog, land surveying, land surveyor, Uncategorized | Tagged FEMA, flood, flood map, flood zone, National Flood Insurance Program, NFIP

Estimate The Costs Of Flood Damage To Your Home

Huntsville Land Surveying Posted on September 28, 2010 by HunstvillePLSMay 22, 2017

The tool below allows you to calculate the costs of flood damage.

Select a home size that approximates yours and then slide the blue button up or down for the expected depth of flooding. The tool will then show you an approximate costs of flood damage incurred. 

To avoid paying the costs of flood damage, have your property surveyed by a licensed land surveying.

Call Huntsville Land Surveying TODAY for a free flood risk assessment of your home. We will review the flooding maps in your area and advise whether we recommend a flood survey. CALL US TODAY at (256) 585-6002. We Give You Peace of Mind.

 

Posted in blog, land surveying, land surveyor, Uncategorized | Tagged costs of flood damage, FEMA, flood, flood map, flood zone, flooding, National Flood Insurance Program, NFIP

Flooding From Excessive Rain Downstream From Earth Dams

Huntsville Land Surveying Posted on September 27, 2010 by HunstvillePLSNovember 22, 2017
Flooding From Excessive Rain Downstream From Earth Dams

Flooding From Excessive Rain Downstream From Earth Dams

An article from the Daily Republic in South Dakota talks about an earthen dam that recently failed there due to a 9-inch rainfall event on July 29th of this year. This rainfall event “overwhelmed its capacity” causing the failure of the earth dam.  There was no report of injury downstream of the dam. This dam was built in 1935, as were a number of them during the Work Programs after the Great Depression.  A Department of Game, Fish and Parks Engineer said that they “were satisfied with the condition of the dam” during inspections in 2007 and again in 2008 and that the dam breach “was caused by an extraordinary natural event and not by any structural weakness in the dam.” (Photograph by Laura Wehde/The Daily Republic)

Earth dams are almost too numerous to count around the country. In fact, you probably live a lot closer to one than you might think. A large number of dams were built over 70 years ago and, in many cases, the owners of the dams are different than when they were built. This makes maintenance and inspection of the dams less regular.

     FEMA estimates “there are over 80,000 dams in the United States”, and that approximately “one third of these pose a ‘high’ or ‘significant’ hazard to life and property if failure occurs.”

In the countries worst dam failure disaster, the South Fork dam failure in May of 1889 killed over 2200 people (almost half of which were under 20 years old) in the town of  Johnstown, PA.  This is known as the “Johnstown Flood.”  A 37-foot high wall of water hit Johnstown, located 9 miles downstream from the dam. The entire city was almost destroyed, including 1600 homes and 280 businesses.

After the failure of the St. Francis Dam in California in March 1928, legislation was enacted in and around California. This, and other later legislation led to life-saving advance warning when the Baldwin Hills dam near Los Angeles, California failed on December 14, 1963. Only 5 individuals were killed because of the advance warning which enabled the evacuation of approximately 16,500.

Even though there have been far less loss of lives in the United States from dam failures since the 1970’s, The Association of State Dam Safety Officials reports that…

    there were 132 dam failures and 434 “incidents” between January 2005 and January 2009.

Of course, I should note that the failure of the earthen levees near New Orleans, LA during and after Hurricane Katrina are purported to be responsible for killing more than 1000 people.

The KaLoko Dam on the Island of Kauai, Hawaii failed in March of 2006 killing 7 people. In November of 2008, the developer, James Pflueger, was indicted for manslaughter and reckless endangerment in relation to the dam failure. The county of Kauai and the State of Hawaii paid out over $9 Million in settlement of lawsuits after the failure.

Cause of Dam Failures

Heavy rains cause overtopping, which is by far the most common cause of dam failures. Dam spillways and structures are typically not designed for more than a 1-percent chance (aka 100-year) storm event. When a rain event exceeds this, the water begins to travel outside of the control spillway. This leads to erosion of the soil on the dam from the excessive amount of water traveling over it. It is also possible for overtopping to occur from smaller rain events because of debris blockage of the outlet structure or spillways or because of settlement of the dam crest.

Foundation defects, including settlement and slope instability, cause about 30% of all dam failures.

Seepage or Piping is the cause of another 20% of U.S. dam failures. Piping is the internal erosion caused by seepage under and through the dam. It often occurs around structures such as pipes through the dam and spillways. Seepage can also be caused by animals burrowing in the dam, by roots of trees growing on the dam, and through cracks in the dam.  All earth dams have seepage resulting from water permeating slowly through the dam and its foundation. But this seepage must be controlled or it will progressively erode soil from the embankment or its foundation, resulting in rapid failure of the dam.

What Should You Do To Protect Home?

Since the failure of a dam causes excessive flooding, one of the best courses of action is to avoid building in a flood zone, unless you elevate and reinforce your home. You should investigate and know your risk from flooding or dam failure. Do you live downstream from a dam? Is the dam a high-hazard or significant-hazard potential dam? To find out, contact your state or county emergency management agency and/or visit the National Inventory of Dams. There are around 2,228 dams on the National Inventory in Alabama. Of those, 636 are listed as high or significant hazard potential dams.

If you live downstream from one of these dams, find out who owns the dam and who regulates the dam. This information should also be available from the National Inventory of Dams.

Next, find out if there is an Emergency Action Plan in place. Again, consult your state or county emergency management agency. (Alabama Emergency Management Agency)

Strangely enough, Alabama is the only state in the United States that has not passed dam safety legislation.

If you want help with investigating a piece of property you are considering purchasing or of one you already purchased, please call Huntsville Land Surveying today at (256) 585-6002.

Posted in blog, land surveying, land surveyor, Uncategorized | Tagged dam failure, earth dam, flood, flooding

Post navigation

← Older posts
Newer posts →

Contact Us

    © Copyright Huntsville Land Surveying
    Huntsville, Alabama
    Phone: (256) 585-6002

    Privacy Policy | Terms of Use

    Web Development and SEO by: AuburnBusiness.com

    This website is a marketing website for Mike Stanley, PLS, Stanley Land Surveying, who provides professional land surveying and engineering services in the Huntsville, Alabama area.

    ↑