FLOOD09060

• County: Statewide
• Community: Statewide
• Basin: Statewide
• Title: Statewide River Rehabilitation and Flood Plain Management Needs Inventory
• Date: 2/18/1998
• Prepared For: State of Colorado
• Prepared By: McLaughlin Water Engineers, Ltd.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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CHAPTER I

INTRODUCTION AND BACKGROUND

The Statewide Needs Inventory was initiated by the Colorado Water Conservation Board in response to
the flood losses, channel conveyance, and stream bank stability problems experienced state wide during
the flood events of 1993, 1995, and 1997. In the 20" Century, Colorado communities have experienced
over $4.9 billion in direct flood damage to homes, businesses, public buildings and utility infrastructure
and suffered unmeasured loss of water supply capacity and environmental quantity.

Between July 28 and August 17, 1997, extreme flooding impacted a thirteen-county area of Colorado as
a result of a monsoonal storm system which stalled over the front range area, Point rainfall amounts of
8.3 inches to 15 inches were recorded. An estimated $200 milli<,m in flood damages resulted in the Fort
Collins/Larimer County area, and an additional $50 million in damages occurred in twelve other counties,
Six deaths were attributed to the flooding and the thirteen-county area received a Presidential Disaster
Declaration.

Stream and riverine flooding has always been, and remains to be, the greatest natural hazard to life and
property in Colorado. Today, flood prone areas have been identified in 268 cities and towns and in all
of the 63 counties in Colorado. Based on estimates by the Colorado Water Conservation Board staff,
250,000 people are estimated to now reside in Colorado's loo-year floodplains with property valued at
over $11 billion. There is a clear need for improved floodplain management efforts to reduce the at-risk
population's vulnerability to flooding, prevent further encroachment into flood hazard zones and preserve
the natural resources and functions of the floodplain areas.

Floodplain areas in stream corridors have many uses other than conveyance of floodwaters; these include:

. Opportunities for outdoor recreation
. Open space
. Preservation of riparian and aquatic wildlife habitat
. Preservation of wetlands.

Such uses of floodplain areas and stream corridors are becoming increasingly important. Little demand
exists for the single purpose flood control project of the past; today. municipalities and other governmental
and private entities with responsibility for flood damage reduction andlor stream corridor management are
demanding multiple purpose projects which not only provide for floodplain management but meet needs

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