Colorado Pipeline and its Implications for Nebraska

 A story in the Colorado newspaper Sterling Journal Advocate reports:

• Colorado will comply with the Republican River Basin Compact by pumping water to the Nebraska State line. 

• Water rights for approximately 15,000 acre feet a year.

• 9,500 acres of irrigated land idled and used for compliance.

• Water rights purchased from land owners for approximately $5,263 an acre.

• Cost per acre foot for the water is approximately $3,333.

• Cost to build the pipeline is approximately $1,400 per acre foot.

• Tax on irrigated acres to the landowners of the Colorado portion of the Republican River Basin are $14.50 an acre

• Subject to approval by the Colorado Legislature and the State of Kansas

• Pipeline construction to begin in fall of 2008 and projected completion date of July 2009

 Full story    http://tinyurl.com/3bmaef

This should concern Nebraska because the Compact will measure Colorado compliance at the Nebraska/Colorado line of the North Fork of the Republican River.  The next gage where the Republican River Basin is measured for compliance purposes is near McCook, which is more than 70 miles from the State Line.  The other gages between the State Line and McCook measure tributary flows.

In dry years, Colorado will place up to 15,000 acre feet of water at the border.  If that water does not make it to McCook because it seeps into the ground before it gets there, then Nebraska will be charged with the consumption of that water and Nebraska will be further out of compliance.  The only way to protect Nebraska from this potential charge is to make sure the water gets to the next gaging station.  In some years, that will be nearly impossible.

 In the years 2002, 2003, 2004 and 2006, not all of the water that entered the stream from Colorado made it to the McCook gaging station.  And, if one accounts for the Nebraska tributary water added to the stream before McCook, then one would recognize the years 2000 and 2001 as a problem as well.  In other words, for seven of the last eight years, not all of the water coming from Colorado made it to the McCook gage.  That means Nebraska removed water coming from Colorado from the stream in the first seventy miles after the stream entered Nebraska. 

 It will be Nebraska’s responsibility to make sure the water that enters from Colorado is not consumed by Nebraska -- either by irrigation wells, trees, or a drought.  If it cannot physically do that, then Nebraska will need to make up for the Colorado water consumed further downstream.

Pumping is inversely proportional to growing season precipitation. 2002 was the driest year in the history of the area.

Stream flows on the Republican have been declining, even though irrigation use has been steady over the last 20 years.  Therefore, there are other reasons for the reduced flow besides irrigation.   The reduction in stream flows began prior to the drought of 2002.  Pumping and precipitation have remained near the average, with the exception of 1993, 2000 and 2002.  If precipitation and irrigation are not the primary causes, then the only other reason for a decline in flow is the increase in conservation practices.  As farms converted from gravity irrigation to center pivots and as more farms used minimum tillage practices and more terraces were added, less water made it to the stream.  Therefore, reducing pumping alone will not fix the problem.  Conservation is the primary cause of less stream flow; but as no one wants to eliminate the conservation practices, it will be a challenge to comply with the Compact without augmenting the stream like Colorado is doing, either via surface water purchases or pumping water into the stream.

Click here for a printable version of this document.   Document is in Word