Friday, February 13, 2009

Water & Wastewater Infrastructure, Supply, and Planning Study - Phase I report, part 2

I have moved on to Chapter 2 of the report - the Water Resource Assessment.
This is the real meat of what the committee was looking at in Phase I. It includes a lot of numbers, graphs, and charts used to summarize things like miles of pipe (water and sewer), number of connections, and how much water and waste is moving through those pipes. An inventory, for the most part.

I won't go through all the boring details by trying to summarize what those numbers say. I'm going to offer a few criticisms and my suggestions for what should have been in this section of the report. But let me start by saying what I thought was good about this section.

They do a very good job of summarizing what has been compiled by Tucson Water (in their recent 50 year planning effort, available here) and the staff of the Tucson AMA (in their planning water budgets and the 3rd Management Plan, both can be found here). They also do a good job of taking the statutory assured water supply (AWS) requirements and explaining them in plain English. They clearly discuss the different elements of Tucson's water supply portfolio and how they fit into the AWS context. Overall, I thought it was a pretty good introduction to the management of water supplies in the Tucson region that can sufficiently educate the average layperson on the topic. For that reason alone I highly recommend reading this chapter.

One point that comes up several times and made me cringe slightly was the claim that Tucson Water was expecting to fully utilize Tucson's CAP allotment this year, as a means of securing our rights to the full amount in the event of cutbacks on Colorado River deliveries in the near future. If you have been following the news here, you would have noticed that the Tucson city council has just voted to approve efforts by Tucson Water to sell 50,000 ac-ft of our allotment this year and perhaps next year in order to make up a budget shortfall the water utility is experiencing due to water sales that didn't meet expectations during the past year and a lack of water connection fees because of the economic slowdown. There is no guarantee they will succeed in selling the water (at least at the prices they are hoping for) but it shows how desperate things are right now financially for a city department like Tucson Water which must meets its entire budget through fees for the services it provides.

The following are some more specific comments/criticisms that I noted while reading the report (with page numbers where applicable):
- in the discussion of recharge projects (pp. 10-11) there was very little discussion of the difference between long-term storage and annual storage and recovery, and how much of each is occurring; how these different strategies are used by Tucson Water; how their use is likely to change over the course of the 50 year planning period -- this is important info for long-term supply reliability planning and requires delicate balancing of present vs. future needs, which come to think of it may just be too complicated and esoteric for this type of report
- their discussion of use of effluent resources (pp. 17-18) failed to adequately discuss the different strategies for using this resource, i.e. recharge, managed vs. constructed (different accrual of recharge credits for each), long-term storage vs. annual storage and recovery; how these different options fit in with Tucson Water's long range planning objectives
- their discussion of available water sources and how they are being managed was generally pretty good, but I thought they could have specifically emphasized the importance of having a diversified water supply portfolio so that long-term drought doesn't have as great an effect on overall water supplies
- following up on the previous point, their discussion of water supply characteristics in the context of conservation programs (p. 30), is overly focused on effects of Colorado River cutbacks, pointing to the crucial weakness in our current supply portfolio; this points to the need to seek alternative supplies to make up for shortfalls from the River, but should also discuss relative costs of seeking those new supplies vs. imposing greater conservation measures in order to make available supplies go farther
- then where they discuss different aspects of conservation programs on pp. 35-37, they give a good general overview of what has been implemented or has been considered for implementation, but there is a glaring absence - use of price to mitigate demand; this option has to be on the table, both to curb demand and to fund conservation measures --- there is also an error in this section where they refer to city ordinances mandating expanded use of gray water and rainwater harvesting, saying that the “ordinances mandate the use of these alternative supplies for new construction beginning in 2010.” My understanding of the new rules is that they require all new commercial development to meet at least 50% of outdoor water needs with rainwater harvesting and require installation of stub-outs for gray water on all new residential construction, but no mandate that gray water actually be used on-site
- their discussion of rainwater harvesting and gray water reuse (p. 37) was pretty skimpy; they presented some case studies to show that the possibility exists, but did not explore in more detail what could be achieved by more widespread adoption of these measures; hopefully this is a topic that will be looked at in detail during Phase II of the study
- on p. 39, the report included a tidbit of information that surprised me because I had never heard of it before (although it shouldn't have been surprising) - they note that the Groundwater Management Act includes provisions to permit pumping of groundwater in AMAs without use of long-term GW credits in the event of shortages on the River. I haven't figured out yet if this provision is time-limited
- they include a long, detailed discussion of climate variability (pp. 40-43) associated with global warming and its potential effect on water supplies in the Southwest; I thought they spent way too much time on the climate change stuff and not nearly enough time on strategies water managers must consider to adapt to new climate realities; the climate change stuff is interesting but instead of spending 3 pages on the science and 1/2 page on adaption, they should have done the reverse
- in their discussion of other potential water sources (p. 46) they characterize importation of groundwater from other basins outside AMAs as a "one time shot"; while the amount of water that could be added to supplies from these basins on a yearly basis might not be that significant, the rules governing this permit essentially a fixed volume of water to be pumped each year (with limits on permissible water level declines) to augment CAP supplies; this could be very useful if managed properly
- the section on other potential water sources was also another opportunity to further discuss the possibilities from rainwater harvesting (either on individual properties or on a larger scale with floodwater retention) and gray water reuse that was not seized; only a very brief mention
- the final section of the report was a discussion of the ADD Water process that the Central Arizona Water Conservation District (CAWCD, the folks who run the CAP) recently initiated to attempt to identify other, available sources of water that could be used to supplement existing supplies within the Tucson and Phoenix areas; they didn't really say much here beyond acknowledging that this process is ongoing, it is more cost-effective for different jurisdictions to work together to secure additional supplies than to fight over the scraps, and how those supplies might be transported and utilized within the existing CAP system; what they did not discuss was where those supplies might come from or how they would be allocated, kind of important issues, but not necessary to resolve now

Next I will work through Chapter 3, Sustainable Water Future. This section looks like a lot of fun and is likely a prelude to Phase II of the study. I'll probably post something on that in about a week.

Also fyi, the public comment period ends on February 18th, which is right around the corner. So get out there and make your voice heard. Also, the first meeting in Phase II occurs on March 19.

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