WSPC05649

• File Number: 8062
• Description: Federal Water Rights - Colorado Litigation - National Forest ISF Claims - Technical Sutdies
• State: CO
• Basin: Statewide
• Date: 9/10/1985
• Author: Unknown
• Title: Technical Studies - Water Information Management System Handbook
• Water Supply Pro - Doc Type: Report/Study

001701

36.2--6

WATER INFORMATION MANAGEMENT SYSTEM HANDBOOK

(f) If 1/2 QR is two or greater then one day is distributed from
the 1/2 OR column (Sa) into the Re column (Sc) to denote recession
days. The remaining days are placed into the Ri column (Sb) for the
rising segment.

(g) Record in column 6 the Q/Qa ratio value related to the
rise-recession segment.

(h) ~ultiply each ratio value by QB to calculate the CFS flow rate
for the rise-recession segment and record in column 7.

(i) COmpute a time-volume coefficient for the rise-recession segment
(that is, total days in column Sa x column 6 x 1.9835) and record in
column 8.

(j) Calculate the volume in acre-feet by multiplying column 8 by QB
for the rise-recession segment and record in column 9a. The values for Re
and Ri are calculated as follows: Re a (column Sc x column 6 x 1.9835 x
QB) and recorded in column 9c; Ri a (column 9a - column 9c) and recorded
in column 90.

(k) Total the values listed in columns 3, 4, Sa, Sb, 5c, 8, 9a, 9b.

)

~.

c. For this example it is assumed that vegetation encroachment potential
is low and no additional flows are required.

d. QL1 Baseflow (row labeled QL1 in ex. 3):

Following determination of the QL1/QB ratio value for baseflow and its
location on the flow-duration curve, the percent time increment for the
duration of baseflow is determined. This increment is the percent time
period between the points for QA/QB and QLI/QB (in this example
266 to 91.56, or 6S.Sa).

(1) Record the percent time limits for QLl in column 1.

(2) Calculate the percent time increment and record in column 2.

(3) Multiply the percent time increment by 365 (for the number of
days in the QL1 baseflow component) and record in column 3.

.
(4) Round to the nearest whole day the days increment and record in
column 4.

(5) Add the number of rise-recession days not used in the 1/2 QR
determinations (in this example 44 days) to the day value in column 4.
These days become part of the baseflow period. Record the total QL1 (in
days) in column 4.