The media has pummeled us lately with plenty of water news. There is one significant Colorado River action that needs review.
Supplemental Environmental Impact Statement (SEIS) for Near-term Colorado River Operations-April 2023
This is the big news that came out last week. Lots of fancy words but this is essentially the United States Bureau of Reclamation (USBR) alternative proposals for Colorado River shortage volumes (cuts) to allow Lake Mead and Lake Powell to recover from current dire low levels. Let's break it down.
What is a Supplemental Environmental Impact Statement (SEIS)?
The National Environmental Policy Act (NEPA) requires an Environmental Impact Statement (EIS) for an action that significantly impacts federal policy, facilities or land. Some call this the "federal nexus". The EIS is more than a statement. It is a huge effort that documents all environmental impacts related to the action. Usually, multiple federal agencies are involved. If the action is modified for some reason in the future, rather than prepare a completely new EIS, the original EIS can be updated, i.e., supplemented. Thus, the Supplemental Environmental Impact Statement (SEIfor Near-term Colorado River Oeprations-April 2023.
What Colorado River action required an EIS/SEIS?
In 2007, USBR adopted the Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead (2007 Interim Guidelines). Yikes-another mouth-full! The 2007 Interim Guidelines provided the original Colorado River water shortage volumes (based on Lake Mead elevation) allocated to the Lower Basin States (AZ, CA & NV). An EIS was prepared for this action and now it is proposed to modify the water shortage volumes which requires the SEIS.
Why is a modification to the 2007 Interim Guidelines Required?
It is clear that the 2007 Interim Guidelines and other subsequent initiatives (Drought Contingency Plan (DCP), Colorado River system water storage incentives, etc.) have not been enough. Lake Mead and Lake Powell are at historic low levels. As of 4/10/23, Lake Mead is 28% full and Lake Powell is 23% full. Drastic action is required to prevent these reservoirs from declining further. The USBR is finally taking proactive steps to impose further water shortage volumes.
What are the three SEIS Alternatives?
No Action Alternative-every EIS/SEIS is required to analyze the status quo, i.e. what are the environmental impacts if nothing is done. In this case, the No-Action Alternative could result in a public water supply, hydroelectric power and environmental disaster. No further discussion needed.
Alternative 1-provides increasing levels of water shortage volumes in 2024 as Lake Mead level declines. For elevations below 1,025', Alternative 1 adds an additional water shortage volume of 983 thousand acre-feet (kaf), which when added to the existing water shortage volume of 1,100 kaf yields a total water shortage volume of 2,083 kaf. Under Alternative 1, these water shortage volumes are allocated to each of the Basin States by historical Law of the River priority. USBR may consider additional annual water shortage volumes of up to 4,000 kaf in 2025 and 2026.
Alternative 2-provides increasing levels of water shortage volumes in 2024 as Lake Mead level declines. For elevations below 1,025', Alternative 2 adds an additional water shortage volume of 983 thousand acre-feet (kaf), which when added to the existing water shortage volume of 1,100 kaf yields a total water shortage volume of 2,083 kaf, i.e., same as Alternative 1. However, for Alternative 1 these water shortage volumes are allocated to each of the Basin States by a constant percentage (13.11%). USBR may consider additional water shortage volumes up to 4,000 kafy in 2025 and 2026.
How do the Alternatives impact Arizona?
Alternative 1 allocates 1,738 kaf (83%) of the 2024 total annual 2,083 kaf water shortage volume to Arizona. See SEIS Table 2.4 below.
Alternative 2 allocates 1,087 kaf (52%) of the 2024 total annual 2,083 water shortage volume to Arizona. See SEIS Table 2.7 below.
What is TA's position regarding the proposed Alternatives?
Alternative 2 is the Preferred Alternative because the additional water shortage volumes for Lake Mead elevations below 1,025’ are determined by a constant percentage (13.11%) of 2021 consumptive use, which is fair and reasonable. A 52% share for Arizona is certainly better than an 83% share proposed in Alternative 1.
Are there any other issues related to the SEIS?
TA has identified two issues in the SEIS that need to be addressed:
Post 2026 Colorado River Operations-Once this critical Near-term period is over and hopefully when Lake Mead levels rise to elevation 1,145’ (Normal Operations), all Colorado River contracts should be cut by 20% across the board (CUT20) because the Colorado River is over allocated and we do not want to end up in this place again. This will become the New Law of The River.
Salton Sea-The Salton Sea has been an integral part of the Salton Basin and the Colorado River for centuries. In the early 1900’s, the Colorado River was diverted in the Imperial Valley, CA for agricultural and municipal uses and stopped flowing into the Salton Basin. The Salton Sea has since been an agricultural sump with enormous environmental issues. The SEIS only mentions the Salton Sea once. The SEIS needs to be expanded to include the impacts of further reductions in inflow to the Salton Sea as a result of the Near-Term Shortage & Contributions. See Water Woes-XIX for more on the Salton Sea.
Comment Letter
TA has provided a comment letter to USBR regarding the SEIS which includes some additional details. You can download TA's comment letter at the link below. You can also email your comments at: CRinterimops@usbr.gov.