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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STREAM CLASSIFICATION

A SCREENING METHOD FOR COLORADO STREAMS

INTRODUCTION

River and stream corridors in Colorado occur in some of the most diverse terrain of the
North American continent, From mountains to high plains, nearly the full range of river process
are evident in the Colorado landscape. Likewise, Colorado's river and stream corridors are
heavily utilized providing botanical, wildlife, and recreation environments.

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Often the backdoor of many communities in the past, river environments are now integrated
into new development and being upgraded to higher land values. In many cases, an improved
river environment is a direct economic stimulus to community development. At the same time,
the natural environment of river has been recognized as a limited resource with a complex
ecology .

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Rivers are also one of the great natural hazards to residents of Colorado. Floods routinely
inflict significant damage to property and result in death and injury. Erosion of stream banks can
degrade the environment of a stream channel, reducing the quality of the corridor as well as
causing property damage. Control of flood damage continues to be a significant challenge for
communities throughout Colorado.

So it is clear that rivers and streams in Colorado are both an opportunity and a hazard. By
their nature, rivers are dynamic accomplishing the work of wearing away the earth's surface and
transporting it to the sea. The landscape we see in Colorado today is testimony to the diversity
of erosion processes. It is important in managing rivers to appreciate that change is essential over
time, and that planning needs to anticipate such change.

It is often difficult to make decisions regarding the resources of a community or the State
when significant uncertainty is present. The management of rivers is such a case. Not only do
rivers flood, but they may change course (either gradually or suddenly). To invest wisely in the
long-term management of rivers means balancing the risks against the potential improvements to
rIVer resources.

The following stream classification presents a simple method to identify risk in river
management projects. Once the risk associated with a project is identified then it can be
compared to potential benefits. The comparison of risk to benefits is subjective since
quantification of project benefits typically does not tell the whole story. It is not the purpose of
this method to elaborate on the many and various benefits that can be obtained in a river
corridor, but simply to identify risk.

It is expected that the primary uses of the classification method will be in early screening of
projects to determine feasibility, and for prioritization of funding.

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