FLOOD06826

• County: Statewide
• Basin: Statewide
• Title: National Economic Development Procedures Manual-Urban Flood Damage
• Date: 3/1/1988
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

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positions on permanent structures such as a spot on a bridge or the top of

a fire hydrant. Bench marks are kept by the U.S, Geological Survey, the

Corps, the U,S,D,A, Forest Service and Soil Conservation Service, the

Bureau of Reclamation, and the Tennessee Valley Authority,

3) Aerial ohotoeraohv, Aerial photos are a commonly used tool for

creating detailed contour maps. The maps can be used with stereoscopic

equipment and field checking to create two-foot contour maps,

4) Survev crews. Survey crews are the most accurate and most costly

way of determining elevations of structures, Survey crews are useful for

very high value property, such as industrial plants and large commercial

establishments, where small differences in elevations can make large

differences in damage estimates, Survey crews are also important in areas

with few permanent bench marks and areas with steep topography, The costs

of survey crews can be reduced by combining their st~ucture elevation

surveys with cross-section survey, and by limiting their work to spot

elevations or reference marks every few blocks,

5) Hand levels, Hand levels are simple devices for estimating the

elevations of structures, This small hand-held instrument can be used to

take readings off bench marks and determine the first floor elevations of

surrounding structures, The user needs no assistance, but simply uses the

level to find a spot on the nearby building at eye level. Hand levels

should be used in circuits to tie back into the original bench marks.

This will serve to verify readings along the circuit,

6) Architectural drawin2s and site Dlans, Architects, developers,
and community building permit officers may keep building records with

first floor, ground and foundation elevations.

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