The compact apportions the waters of Costilla Creek between
Colorado and New Mexico.
Costilla Creek, a tributary of the Rio
Grande, begins on the west slope of the Sangre de Cristo Range
and crosses the State boundary three times above its confluence
with the Rio Grande in New Mexico.
Article IV of the compact
provides for the apportionment of the natural flow of Costilla
Creek and the allocation of water from Costilla Reservoir and
Eastdale Reservoir.