WAP 2001-2002 PRRIP

• Description: Staff Notebook for Platte River Research Cooperative Agreement ‎(aka Platte River Recovery Implementation Program or PRRIP)‎ Water Advisory Committee ‎(WAC)‎ Meetings including memos, comments, emails, minutes, letters, agendas, notes, etc. 2001-2002
• State: CO
• State: NE
• State: WY
• Basin: South Platte
• Water Division: 1
• Date: 1/1/2001
• Author: CWCB Staff
• Title: Staff Notebook for Platte River Research Cooperative Agreement Water Advisory Committee ‎(WAC)‎ Meetings for 2001-2002
• Water Supply Pro - Doc Type: Meeting

values, the total amount of open water acres was calculated from the existing values. The open
water acres value was calculated for each reach by dividing the July CL value by the average
July evaporation. The CL value then could be calculated for October to April by multiplying the
open water acres for each reach by the monthly evaporation.'
Keystone to Grand Island Calculations
All CL values for these reaches were recalculated using the latest evaporation and 1993 river
area data.
The CL values for the reaches between Keystone and Cozad were calculated with using the
North Platte data, the CL values for Cozad to Kearney were calculated using an average of the
North Platte and Grand Island data, and the CL values for the Kearney to Grand Island reach
were calculated using the Grand Island data.
The average open water and sandbar and vegetated island areas from bank to bank were digitized
from 1993 Digital Orthophoto Quarter Quadrangle's. Only vegetated islands less than 20 acres
in size were included for the calculations. On islands over 20 acres, only a 100' buffer strip was
included in the island area. It was thought that islands larger than this size had sufficient
recharge in the island interior to meet the evapotranspiration needs of the interior vegetation.
In the past for some reaches, conveyance losses varied based on the flow. Because there was not
enough information available to determine the areas under various flow conditions, it was
decided to give each CL a flat value.
All tables used in the calculations can be found in Appendix A.
Results
Reach
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
State Line - Minatare
4
3
4
8
8
12
13
11
6
6
4
4
Minatare - Bridgeport
3
3
3
7
8
11
12
10
7
6
3
3
Bridgeport - Lisco
y 5
5
5
10
12
16
18
14
10
8
5
5
Lisco - Lewellen
5
S
5
10
12
16
i 18
15
10
8
5
5
Keystone Sutherland
2
2
3
6
7
9
10
9
7
5
2
2
Sutherland - Maxwell
6
6
7
15
18
22
25
22
18
12
6
6
Maxwell -Cozad
4
4
5
11
12
16
18
16
13
8
4
4
-
Cozad - Overton
5
5
6
15
18
22
24
20
17
11
5
5
Overton - Kearney
7
7
8
21
26
32
35
30
25
16
7
7
Kearney Grand Island
14
14
15
_ 49
60
75
77
64
56
36
14
14
*All Values in CFS
The loss values increase downstream of Overton because of the wider channel and longer river
length between Kearney to Grand Island.
Residual Losses
0 ' For a more detailed explanation of these conveyance losses see the North Platte River settlement documents.