WSPC02533

• File Number: 8040.950
• Description: Section D General Studies-General Water Studies
• State: CO
• Date: 1/1/3000
• Author: DOI
• Title: HCRS Rivers Inventory-Nationwide Rivers Inventory-Informational Bulletin 2-The Inventory Process and Potential Future Uses
• Water Supply Pro - Doc Type: Project Overview

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NATIONWIDE RIVERS INVENTORY

The western regions of the Heritage Conservation and Recreation
Service (HCRS) are engaged in a study to determine the environmental
"health" of all major rivers in the western united States and to identify
which remaining free-flowing streams are best suited for conservation
purposes. We are developing a detailed data base on approximately 20%
of the major western stream courses. The resulting information is in-
tended to be useful to all levels of government and private citizen
interest groups. Using this data, we intend to assist State and
local river conservation efforts.

THE INVENTORY PROCESS

At the onset, two irrlportant decisions were made regarding the inventory.
The first was to conduct it by physiographic areas, and second was to
inventory all rivers and streams that were at least 25 miles long from
their source to mouth. The reason for these decisions is discussed
below.

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(1) Physiographic Areas--Rivers within a given physiographic area tend
to have a particular pattern of relief features or land forms which
differ significantly from adjacent areas. Therefore, such rivers can
be compared among themselves to identify the best rivers within a
given area. Using physiographic areas ~lso ensures that a balanced
representation of various types of rivers throughout the country would
be identified.

(2) Length--Identification of all rivers and streams 25 miles or longer
for inclusion in the initial stages of the inventory was a logical
approach based on guidelines found in the "Guidelines for Evaluating
Wild, Scenic, and Recreational Rivers Proposed for Inclusion in the
National Wild and Scenic Rivers System Under Section 2, Public Law
90-542."

As a result of the Eastern Rivers Inventory, there was concern that
important river segments were being eliminated under the 25-mile
~imitation. Therefore, segments of the initially identified rivers
as short as 5 miles in length will be considered in the Western Rivers
Inventory.

There are six basic steps, or filters, to the inventory process. Each
is discussed separately below.

Filter 1, Length--This filter is used to identify all rivers or streams
25 miles or longer from source to mouth. This was done nationwide by
the Southeast Regional Office with the qualifying rivers being identified
on USGS 1:500,000 scale maps. The maps and lists of rivers were turned
over to the regions according to physiographic section.

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