WSP07478

• File Number: 8272.600.60
• Description: Colorado River Basin Salinity Control Program - Basin Member State Info - Utah
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/1/1982
• Title: Salt Uptake in Natural Channels Traversing Mancos Shales in the Price River Basin - Utah
• Water Supply Pro - Doc Type: Report/Study

feeder channela (channel orders 3 and 2,
respectively) are shown. The main stem of
r\'Coal Creek was subdivided into ten reaches of
~qual length, each approximately 0.82 mi long
o(Figure 6.2). Each reach waa aasumed to have
d uniform channel cross-sect ion' and salt
producing potential. A constant Muskinghum
routing coefficient was used for each reach
(Table 6.1).

Subbasin 9

1

Subbasin 8

2

Subbasin 1

Headwater basef10w, channel seepage, and
groundwater inflow values are also liste!,! in
Table 6.1. Precipitation and precipitation
excess values obtained from the RAIN and
HYDRGY subroutines are given in Appendix E.
Table 6.2 gives routing coefficients for
surface runoff and for tributary channels
(orders 1, 2, and 3).

For overland flows, coefficienta for
predicting salt pickup as a function of
geologic member are given by Table 5.2.
Channel (orders 1, 2, 3, and 4) salt pickup
characteristics are listed in Table 6.3.

The model was run in timestepa of 20
minutes, and steady state conditions were
achieved after 90 timesteps. An illua-
trative model response for 2 mm of surface
runoff is illustrated in Figure 6.3. The
salt concentration peaked at the beginning of
the flood hydrograph and then rapidly dropped
to a low value during the bulk of the flow.
A t the ta 11 of the flood hydrograph, the
concentration slowly rose again because of
reduced dilution. Finally, the concentration
dropped as inflows from lateral channels
ceased, and the remaining flow drained
from storage in the main channel.

In the model, the salt concentration may
be linearly adjusted by varying the salt
loading coefficients. The second salt
concentration rise may be varied independent-
ly of the first by adjusting. 1) the time of

3

4

Subbasin 7

~

Subbasin 2
Subbasin 3

5

6

Subbasin 6

~

7

8

9

Subbasin 5

~ ..

Subbasin 4

10

Figure 6,2. Model representation of Coal
Creek.

Table 6.1. Primary channel characteristics.
Reach Wetted Groundwater Concentration Channel Muskinghum
Number Perimeter Inflow Groundwater Seepage Routing
Coefficients Coefficients
A B m3;min mg/l m3/min K(min) X(min)
1 2.1 0.4 0.0 2200 -0.00056 30. 0.3
2 2.1 0.4 0.0 2200 -0.00056 30. 0,3
3 2.1 0,4 0,0 2200 -0,00056 30. 0.3
4 2.1 0,4 0.0 2200 -0,00056 30. 0.3
5 2,1 0.4 0.0022 2200 -0.00056 30. 0.3
6 2.1 0.4 0,0 2200 -0.00056 30, 0.3
7 2.1 0.4 0.0 2200 -0.00056 30. 0,3
8 2.1 0.4 0.0 2200 -0.00056 30. 0.3
9 2.1 0.4 0.0 2200 -0,00056 30, 0.3
10 2,1 0.4 0.0 2200 -0.00056 30. 0.3
Headwater base flow = 1. 704 m3fmin.
58