FLOOD11755

• County: Statewide
• Basin: Statewide
• Title: Guidelines and Specifications for Flood Hazard Mapping Partners - Volume 1: Flood Studies and Mapping
• Date: 4/1/2003
• Prepared By: FEMA
• Floodplain - Doc Type: Educational/Technical/Reference Information

Guidelines and Specifications for Flood Hazard Mapping Partners [April 2003]

1.4.2

Topographic and Flood Hazard Data Development [February
2002]

Tapa & Flood
liazard Data
Development

Preliminary I
Post-Preliminary
Processing

The following activities are to be completed during the Topographic and Flood Hazard Data
Development sub-phase for a Flood Map Project that will include new or updated flood hazard
data:

. Field survey and topographic data development, including aerial topc:>graphic surveys,
cross-section surveys, hydraulic structure surveys, and establishment of vertical control
and location of qualifying bench marks;

. Flood hazard data development, including detailed flood hazard analyses, approximate
flood hazard analyses, and redelineations of floodplain boundaries based on updated
topographic data; and

. Creation and submittal of draft materials, including floodplain mapping (i.e., work maps),
digital files for GIS-based applications, and FIS report components.

The Topographic and Flood Hazard Data Development sub-phase includes colkcting or
acquiring the necessary topographic and field data and conducting detailed and/or approximate
studies and/or redelineating floodplain boundaries using flood elevations from the effective
FIRM and PIS report. Thus, this component is required only for Flood Map Projects that will
include new or updated flood hazard data.

The topographic and flood hazard data development path includes the steps summarized below.

1. Field survey and topographic data development, including:

· Aerial topographic surveys;

· Cross section surveys;

· Hydraulic structure surveys; and

· Establishment of vertical control and location of qualifying bench marks.

1-57

Section 1,4