WSP06720

• File Number: 8111.831
• Description: Arkansas River Compact Administration - Article VIII Investigations
• Basin: Arkansas
• Date: 1/1/1985
• Author: David Pope
• Title: Report to the ARCA regarding Article VIII ‎(H)‎ Investigation of Alleged Violations of the Arkansas River Compact
• Water Supply Pro - Doc Type: Publication

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

12

reflects the increased usable stateline flows which resulted from

the Compact and operation of John Martin Reservoir.

Another sig-
",,4\Jf.Q.
From 1974 to ~\'i7q-gfo-

t v'~ I.
1982 the slope of the curves are less than at any other time dur \q~, Q~{~
~e""
ing the study period. indicating a change in the relationship ~~

nificant break in slope appears starting in 1974,

between usable stateline flows and available water supply in the

basin.

The diagrams of Usable Stateline Flow vs. John Martin Reservoir

Inflows and John Martin Reservoir Outflows (sets 2 and 3) also

show breaks in slope corresponding to the same periods as noted

for the double-mass diagrams inset 9. It should be noted that

the flows above John Martin Reservoir (the sum of the Arkansas

River at Las Animas and the Purgatoire River at Las Animas) de-

clined as a result of the Compact in 1949, Some declin~was anti-

c i pa ted and resu 1 ted by remov ing the downs tream call f ro'Jil<obe:low

John Martin Reservoir and thereby allowing the upstream users to

increase their diversions, When evaluating the usable stateline

flows, itis not appropriate to directly compare the post-comp~ct

and pre-compact relationships between usable stateline flows and

the combined flows at the Las Animas, Observing the diagrams for

the post-c~mpact period. it can be seen that a relatively constant

relationship was maintained until the last 11 years of record, In

this time period (i.e, 1974 to 198A). the usable stateline flows

declined in relation to the inflows to John Martin Reservoir.