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jessho
Posts: 6
Joined: 11/13/2008
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An important issue |
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Locally, we had substantial damage from hurricane Ike, which has brought to light an unfortunate comedy of errors:
A surveying company, and surveyors are looking at professional and civil problems due to using a USGS monument that has been determined is around 3' lower than was recorded years ago. Otherwise, existing homes are unable to be insured due to the elevation above sea level. Some home would have avoided flooding if the property owners had built to the higher elevation the survey indicated. The surveyors certified the elevations, but used the benchmark that supposedly was placed in soil that subsided 3 feet. The property owner have a legal leg to stand on, but unfortunately all of their efforts for compensation may only end in judgements, if anything. The professional reputations, and licensing of the surveying companies is up in the air until a final determination.
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Monday, February 16, 2009 at 5:07:31 PM |
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Isleno
Posts: 40
Location: Gonzales, La USA
Joined: 10/20/2008
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Re: An important issue |
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| This is not a new problem. FEMA policy in areas of rapid or significant subsidence has been to rely on the most recent published values for vertical marks. It is not suffcient to file a value for a benchmark and then rely upon that value years later. NGS marks or CORPS values must be retrieved at the date that the work is performed. Coastal areas of the Gulf of Mexico are experiencing significant movement. Changes in the vertical datum have also been occuring. FEMA maps, regulations and policies do not accomodate vertical changes very well at all. I have been battling FEMA, NGS and others over the issue of vertical movement since 1975. The only answer seems to be frequent updating of vertical data and frequent revisions of flood hazard area mapping.
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