WSPC03939

• File Number: 8460.500
• Description: Platte River Basin - Endangered Species Issues - South Platte Recovery Program
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 12/5/1995
• Author: Matthew J Cook
• Title: South Platte Agreement - Groundwater Recharge as Augmentation for Restoring Wetlands Along the Central Platte River Nebraska - Final Report
• Water Supply Pro - Doc Type: Report/Study

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River, 26,000 acres of river channel have been converted to other uses. The

average loss is 285 to 320 acres per mile of river channel in the Big Bend reach

(Currier et. al. 1985). Sidle et.al (1989), Williams (1978, and Eschner (1981)

have also performed detailed analyses of the decline in channel width in a

number of river segments. Concerning the grassland complex, losses of wet

meadows (part of the grassland complex), sandhi lis prairie, alfalfa, and

emergent wetlands on lands within 3.5 miles of the river channel have been

substantial. In the Big Bend reach grassland 10iSses have ranged from 56% near

Odessa to about 80% near Grand Island. The average loss of the grassland

complex within 3.5 miles of the river channel has been estimated at 72% (Currier

et. al. 1985). In summary, the Platte River has undergone the following major

changes since pre-settlement times (from Currier et. al. 1985):

1. 65% to 79% reduction in channel width in the Big Bend reach of the
Platte River and a corresponding increase in encroachment of the
channel by wooded vegetation.
2. 58% to 87% reduction in the areal extent of the Platte River channel
as a result of woody vegetation encroachment.
3. 72% loss of the grassland complex within 3.5 miles of the Platte River
4. Extensive irrigation, ditching, and drainage of lands adjacent to the
Platte River channel.

These findings have a serious impact on the required habitat for the

whooping crane. Several eharacteristics common to ideal whooping crane roost

sites were described by Johnson and Temple (1980) including:

1. Wide channels;
2. Unveaetated areas;
3. Fine Substrate, usually sand;
4, An unobstructed horizontal visibilitv from riverbank to riverbank of at
least 1500 feet upstream and downstream:
5. Open visibility overhead. absence of tall trees. tall and dense shrubs.
or hiah banks near the roost:
6. Shallow water except for the main channel;
7. Slow flow, about 1-4 miles per hour, although water in the main
channel may be moving faster;
8. Proximity to a suitable foraaina site such as a wet meadow (usually
within 1 mile);
9. A distance of at least 0.25 miles from roads, houses, and railroad
tracks.

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