Water Management Study: Phase 1 Report

• File Number: 8461.100
• Description: Adaptive Management Workgroup
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 1/29/2008
• Author: Boyle Engineering, Ecological Resource Consultants, BBC Research & Consulting, Lytle Water Solutions
• Title: Water Management Study: Phase 1 Report
• Water Supply Pro - Doc Type: Report/Study

• North Platte at North Platte, NE
• Platte River at Brady, NE
• Platte River near Cozad, NE
• Platte River near Overton, NE
The action stage is when a river is three quarters bank full. Calculated rating tables
for specific river gage sites are used to determine flows for minor, moderate, and
major flood stages. The flood stage value cited on the NWS charts correlated directly
with a flow value for the majority of the gages. Flood flows corresponding to the
NWS flood stages were not available as direct take-offs from the NWS charts for the
Cozad, Lewellen, Brady and North Platte at North Platte gages. These gages required
use of the rating table and flow equations defined by the Nebraska DNR to calculate
the corresponding flow for flood stage. The rating tables were provided by the
Nebraska Department of Natural Resources (DNR). The estimated flood flows are
presented in Table 3-2 entitled, "Estimated Flow at NWS Flood Stage for Platte River
Reaches".
The Central Nebraska Public Power and Irrigation District (CNPPID) and Nebraska
Public Power District (NPPD) divert available flows up to the diversion capacity
throughout the year, including Program water. Program water may also be
intentionally re-regulated within the Districts' systems and/or Program water may be
intentionally bypassed to the river under specific conditions described in the Program
Document Water Plan (Attachment 5, Section 1), and current and future agreement(s)
with the Districts.
The following are the known limitations and capacities, as presented in the WMS
Request for Proposals (RFP), within the Districts' systems and the North Platte River
below Lake McConaughy that affect the delivery of Program water. These limitations
and capacities were confirmed during discussions with NPPD and CNPPID staff.
The capacities discussed below are also presented in Table 3-3 entitled, "Table of
System Capacities", and annotated on Figure 1-1.
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PRRIP - Draft Water Management Study, Phase I