WSP04706

• File Number: 8200.400.30.C
• Description: La Plata River Compact
• Basin: Colorado Mainstem
• Date: 9/1/2001
• Author: Kenneth W. Knox
• Title: The La Plata River Compact: Administration of an Ephemeral River in the Arid Southwest
• Water Supply Pro - Doc Type: Publication

Issue 1

THE LA PLATA RIVER COMPACT

117

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interstate and intrastate water users who may not have full
appreciation or knowledge of transit losses, the travel times between
key locations, and the changing river call priority."
Contested issues of water entidement and delivery often occur over
the infrequent rainstorms that provide a short-term increase in
streamflow within a confined reach of the river. Water users
throughout the La Plata River Basin justifiably demand incorporation
and administration of these additional streamflows within the priority
system of each state. Similarly, the downstream state water officials
also seek assurance to include and deliver these flows under the
Compact. Unfortunately, it is often impractical to distribute small
increases in streamflow that result from a twenty minute rainsquall that
passes through a small portion of the basin.
The authors, of the La Plata River Compact recognized the
intricate balance between maximizing the beneficial use of water and
assuring its equitable apportionment among the states in an
occasionally volatile natural environment." For that reason, the
Compact authors instructed state water officials that upon substantial
delivery of water 'to meet Compact obligations at the state line, they
should disregard the minor and compensating irregularities in flow or
delivery. 55

V. CONCLUSION

The average annual streamflow for the La Plata River pales in
comparison with the yield of other m~or interstate river systems that
originate in the mountains of Colorado." Nevertheless, water users in
Colorado and New Mexico who rely upon streamflows in the arid La
Plata River Basin for irrigating their crops or filling their pitchers of
drinking water place no less value and importance on it as a precious
resource. Since the adoption of the La Plata River Compact seventy-
nine years ago, the La Plata watershed has enjoyed a few periods of
abundant water supply and suffered though many droughts. However,
one measure of the success of an interstate compact is whether it has
ever been the subject of interstate litigation. While Hinderlider v. La
Plata River and Cherry Creek Ditch Co." tested the weight of interstate

83. The river call priority will often change on a daily basis toward early
appropriation dates in the 1890s for the La Plata River during periods of rapidly
declining streamflows. It is the priority of the ditch or structure exercising its
authority to demand curtailment of junior water rights in time and amount necessary
to provide sufficient water to satisfy its demand.
84. See La Plata River Compact, COLO. REV. STAT. art. II, ~ 37-63-101 (2001),43 Stat.
796,797.
85, See La Plata River Compact, COLO. REv. STAT. art. 11(5), ~ 37-63-101 (2001),43
Stat. at 797.
86. 2 U.S. GEOLO,GtCAL SURVEY, WATER RESOURCES DATA: COLORADO: WATER YEAR
1999, at 154, 279, 387, 409, 422 (1999). The average streamflows leaving the State of
Colorado are as follows: La Plata River (26,100 acre-feet), Colorado River (4,632,000
acre-feet). South Platte River (408,900 acre-feet), Arkansas River (163,200 acre-feet),
and the Rio Grande River (328,400 acre-feet). [d.
87. Hinderliderv_ La Plata River & Cherry Creek Ditch Co., 304 U,S. 92 (1938).