FLOOD11043

• County: Statewide
• Basin: Statewide
• Title: Map Modernization Implementation Plan for Colorado
• Date: 8/1/2002
• Prepared For: FEMA Region 8
• Prepared By: CWCB, UDFCD
• Floodplain - Doc Type: Educational/Technical/Reference Information

Mapping Plan for Colorado

3.0 Meeting FEMA's Map Modernization Implementation Goals

In its request to the state for assistance in preparing MMIP documents, FEMA made reference to the three
underlying GPRA goals for the Map Modernization effort. Paraphrased, those goals are:

. Reduce the average age of the maps.
. For the highest-ranked 15% counties in each state prepare digital maps.
. Prepare floodplain maps for a significant number of unmapped communities.

CWCB's prioritization methodology has incorporated four parameters (population, population growth,
age of maps, and unmapped communities) to address these goals. In addition, CWCB specifically plans
to use first-year Map Modernization funding to start preparing digital floodplain information for the top
10 to 16 counties in the state (10 counties = 15% and 16 counties =25%), based on results of the map
need prioritization methodology and dependent on ultimate funding levels and each high priority county's
ability to prepare digital maps.

3.1 Reducing the A verage Age of the Maps

The oldest FIRMs in Colorado are approximately 25 years old. The CWCB methodology used a scale of
o to 5 for the priority analysis. New map panels (2002) received 0 points. Map panels from 1 to 5 years
old received 1 point, map panels 20 years old and older received 5 points, and so on. Ten of the "top 16"
high priority counties in Colorado have an average panel age of 10 years or more. Clearly preparing new
digital maps for at least 10 of these counties will greatly reduce the average age of map panels within the
state. While the CWCB's primary goal in floodplain mapping is to prepare floodplain maps where they
are most needed the goal of reducing map age will inherently be met in the process.

3.2 Preparing Maps for Unmapped Communities

108 communities are deemed "unmapped" by the CWCB. They include communities with flood hazards
for which no agency has published floodplain maps (at least to CWCB's knowledge). In addition, they
include newly incorporated municipalities for which no specific FIS has ever been prepared but which
include areas mapped for the county in which they are located, communities for which have had mapping
prepared by other agencies besides FEMA, and communities that the CWCB has deemed not floodprone.
Taking all of those factors into account, CWCB developed a methodology that scored communities from
o to 5 and then provided composite scores for the entire county, including municipalities. Within the top
16 counties there are a total of 18 unmapped communities that are floodprone, out of 108 unmapped and
floodprone communities statewide. Ten of the "top 16" counties would make a good initial contribution
to the reduction of the backlog of unmapped communities in Colorado.

3.3 Preparing Digital Maps for the Top-Ranked Counties

CWCB specifically plans to use first-year Map Modernization funds to initiate digital mapping in at least
10 of the "top 16 counties". Those 16 counties, as determined by the CWCB prioritization methodology,
represent the top 25% of 64 Colorado counties. Within 8 of the 16 counties there are already digital
floodplain mapping projects underway. Six of those eight counties are within the Urban Drainage &
Flood District and are working cooperatively with the District (and with FEMA) to prepare digital
floodplain maps. Communities within several of the other counties have Geographic Information
Systems (GIS) in place or under development that would lend themselves to digital floodplain mapping.
CWCB will strongly encourage all new floodplain mapping to be prepared digitally from their inception.
Counties that do not wish to pursue digital mapping may very well be bypassed by CWCB with counties
wanting digital mapping moving up in priority.

12/26/2002

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