13 Feb 2014

Collateral damage from water transfers

Jim Brobeck, Water Policy Analyst at AquAlliance sent me this insightful comment:
Jay Lund, David Zetland and Robert Glennon are well known water policy analysts who consider water transfers to be a primary strategy for wise water supply management. The source of transferable water is river entitlement that agricultural irrigation districts control. The district farmers either fallow land to make water available or pump groundwater to replace the marketed river allocation. The latter method is called “groundwater substitution”. When author Glennon visited Chico he was asked if he included groundwater substitution water marketing in his recommendations for conserving water. He emphatically said such a strategy is “Bogus!” Jay Lund responded to the same question by saying that groundwater and surface water are connected and that water pumped from the ground depletes the surface flow. The Sacramento River is a losing stream all the way to Red Bluff during irrigation season.

In 2013 Glenn Colusa Irrigation District (GCID) sold 5000 acre/feet of Sacramento River water to San Luis Delta Mendota Water Authority (SLDMWA) and pumped replacement water from the regional shared Tuscan aquifer. The wells were created with State taxpayer water bond money as “aquifer performance test” infrastructure exempt from detailed environmental review. The Aquifer Performance Test was accomplished one year and showed recharge water came from the foothills to the east located in Butte and Tehama counties.

In 2014 GCID has issued a Notice of Preparation of an Exemption to pump for two months from the “test” wells into the main canal to water trees located in Glenn and Colusa counties on land with depleted aquifer levels. The relentless demand for groundwater from an irrigation district with infrastructure designed to distribute river water is creating political and environmental conflict.

USBR and SLDMWA are in the 3rd year of preparation of an EIR/EIS to transfer up to 600,000 A/F of Sacramento Valley water through the Delta. A large portion of the proposed marketed water would be produced with groundwater substitution. Supporters of the “market” strategy for water supply must be clear about the types of water sales that would contribute to a sustainable resource. Groundwater substitution using aquifer systems that are approaching imbalance will deplete streamflow, impact groundwater dependent ecosystems (oak groves, springs and riparian zones), threaten land subsidence and inspire political discord.
After seeing this text, I asked Jim:
But isn't the problem in definition of "origin"? People who draw groundwater from a well that's close to a river may not impinge legally on surface water that's physically connected. You're right that hydrology is connected globally when you allow for enough time, but those connections do not matter in the short run, when it may be useful to transfer water.
He sent this reply:
Time scales are relative to age of observer and duration of residency.

I have participated in the Butte County Water Advisory Committee for about 10 years. We have a Basin Management Objectives (BMO) monitoring program in place that sets "alert stages" based on historic water levels. Over this short time span I have watched key monitoring well levels decline year after year. There has been no enforcement of BMO non-compliance.

One of my colleagues farmed here with his family since the early 20th century. Their hand dug well has long since dried out and been replaced with deep wells. When he was a boy they would take their share of spring run salmon by wading in the creek with a pitchfork. The adult fish were swimming toward their foothill cool pools to wait out the summer and spawn in the fall. The farm could water their livestock in the creek year around. Now that stream, and many others, are dry most of the year. Spawning habitat is long gone and rearing habitat only exists near the confluence of the stream and the Sacramento River.

Big Chico Creek, a modest tributary, goes underground several miles away from the confluence during the summer orchard irrigation season. Production wells exist less than a mile from the creek. The water returns to the creek (even without precipitation) in October when the orchard pumps power down.

Irrigation districts that are starting to use the aquifer as a backstop to their river entitlements claim that their production quantities are minor in the grand scheme of existing use. At the same time there is a creeping increase in groundwater irrigated orchard use added to the ever-increasing "existing" use. Does the annual increase in GW extractions constitute a "change of use"? Cumulative impacts are not being effectively analyzed.
[DZ's] Bottom Line: The short run means different things to different people, so it's important to agree on "short run impacts" before transferring water out of its watershed.

No comments:

Post a Comment

Note: only a member of this blog may post a comment.