Jack Schmidt on New Mexico water managers’ pushing 1,700 cfs down the Rio Grande in the middle of December to tidy up our annual Rio Grande Compact accounting:
Thanks for the reminder of the tragedy of moving water at the wrong time of year when that water provides no ecological benefit. If that water were moved in spring, it would do so much good. Sad.
(Elevated from the comments here, where we also learn that our 1,700 cfs here, the highest sustained flows of the year, are about the same as the Palo Verde Irrigation District’s typical summer diversions from the Lower Colorado River. I love this blog’s readers.)
So much potential flexibility in managing streamflow is sacrificed to the calendar year deliveries, which lead anomalous high flows before end of December in many years. If accounting period for previous year deliveries could be extended until the start of irrigation season, we could realize ecosystem benefits.
Read Article 13 of the Compact which allows “non-substantive changes” to be made by unanimous consent (in years ending in 8 or 3). Texas and Colorado commissioners have expressed willingness tones to consider redefining the Water Year. However, New Mexico was opposed. I insist that there is an opportunity here, despite ISC’s curious opposition…
So much potential flexibility in managing streamflow is sacrificed to the calendar year deliveries, which lead anomalous high flows before end of December in many years. If accounting period for previous year deliveries could be extended until the start of irrigation season, we could realize ecosystem benefits.
Read Article 13 of the Compact which allows “non-substantive changes” to be made by unanimous consent (in years ending in 8 or 3). Texas and Colorado commissioners have expressed willingness to consider redefining the Water Year. However, New Mexico was opposed. I insist that there is an opportunity here, despite ISC’s curious opposition…
Less evaporation in December. In the present political context, I wouldn’t end a comment with “Sad.” Also, I think anything about discrimination should be phrased in a way that would not draw attention.
I wonder if Jack’s perspective would be different if he understood the high flow rate is intended to move sediment and thereby increase the channel capacity of the Rio Chama for flows next Spring and beyond?
Without increased channel capacity, water would go into flood storage next Spring rather than flow downstream to augment the mainstem Rio Grande snowmelt runoff.
Rolf – Are you suggesting that, absent the need to clear the Rio Chama sediment, we would not be moving the water at this time of year, that we could, then, move it in spring as Jack would prefer? That is not consistent with the long history of this practice of moving the accounting water in winter, before the end of the year, even absent the Rio Chama sediment plug chaos – a practice that Jack, Steve Harris and others have taken issue with for many years. The explanation Mike Carpenter offers has long been offered as the reason – less system losses when we move it now. But isn’t that the real discussion that needs to be had, not “We need to blast out the Chama sediments right now.”?
Another significant example of the “wrong time of year” is conveyance of water supplies through the California Sacramento-San Joaquin Delta. Pumping restrictions from January through June, ostensibly to reduce entrainment of salmonids, limit what can be pumped into the California Aqueduct and Delta-Mendota Canal from upstream reservoirs such as Shasta and Oroville. The unintended consequence is very large flows to move water in the Sacramento River in July through October, when it is not as ecologically beneficial — and lethal temperatures in the river from April through June.