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Where Has All The Water Gone, Part Three |
Glenn Walsh | 8/28/08
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The Pagosa Area Water and Sanitation District has published their draft Water Conservation Plan and made it available for review both online and at government offices around the County.
The plan is comprised of three parts. Part one is an admirably candid assessment of the district’s present state, which details remarkable gains and losses. The district has managed to reduce average water use per customer by 25% over the past ten years, but still loses over 34% of treated water (nearly 700 acre feet) as that water is delivered through the 290 miles of deteriorating pipes which comprise the PAWSD system.
 Part two of the report reiterates the fictitious water demand projections from the district’s engineer Steve Harris which have made the case for a 35,000 acre foot reservoir at Dry Gulch — which would serve a County population of 160,000 in the year 2100. That case was rejected by the Colorado Supreme Court last fall.
Part three of the report provides specific recommendations of conservation measures and programs that PAWSD intends to implement over the next ten years. In many ways, part three combines the analytical rigor of part one with the statistical shiftiness of part two.
The district’s consultant Great Western Institute and Water Conservation Director Denise Rue-Pastin have presented the district with a superb, wide-ranging and detailed plan which presents PAWSD with the opportunity to make great strides.
But PAWSD has, apparently, decided to take baby steps.
One statement in the report is difficult to understand. “PAWSD has limited resources to implement its water conservation program.” With reservoir costs predicted to increase to $20,000 per acre foot over the next ten years by the Plan itself — giving the district’s 35,000 acre-foot model a price tag of $700 million — why does the district have limited resources for measures which are 90% cheaper?
There appears to be a reluctance to conserve water where measurable success would undermine the district’s legal case and public relations for their 35,000 acre foot Dry Gulch AF project.
Why else would the district decide to invest so little in programs and measures which could save so much?
Again, PAWSD is projecting that reservoir systems will eventually cost $20,000 per acre foot. Consider that widespread use of the most cost-effective water saving appliances, which account for well over half of inside and outside use, could save almost half our present usage.
The top ten water saving fixtures and measures from the PAWSD water conservation plan are set out in the table below. Many of the most effective of these fixtures cost about 10% of the cost of reservoir development, including installation — and they pay for themselves in reduced water bills within four years. If the district could employ a mix of rebates, regulations and monthly pricing to install these devices in every home and business in the district, water use would be cut almost in half.
The savings from installing these devices in all homes and businesses by 2018 would almost double, according the Plan's numbers. Yet, the rebate programs proposed by PAWSD aim to replace less than 10% of these fixtures over the next ten years:
The total reservoir cost savings possible over the next ten years — if rebates and regulations place only these least expensive fixtures in every home — over $30 million.
So, why has PAWSD decided to pursue only $2 million of these savings?
Luckily, new homes and businesses will be installing many of these devices, even though PAWSD will only extend rebates to a small fraction of these new units. Low flush residential toilets are in 70% of Archuleta homes in 2008, and will rise to 90% by 2018 thanks to federal requirements on new units. Commercial high efficiency toilets comprise only 25% of local market today, but will be nearly 60% by 2018, again thanks to requirements placed on new growth. High efficiency commercial urinals comprise only 27% of such fixtures today, but will comprise over 60% by 2018. But rebates for older wasteful toilets are planned for less than 10% of such fixtures. These fixtures pay for themselves in a few years.
Adding up these numbers leads to one conclusion: even with a very modest plan, water conservation is going to save this community thousands of acre feet of water, and tens of million of dollars over the next thirty-five years. Over 213 million gallons of treated water in 2008 – over half of potable water billed to customers — is being used in residential and commercial toilets and urinals. Only about 35% of these fixtures are high efficiency today. About 70% of these fixtures will be high efficiency units in 2018. These fixtures are three times as efficient as the fixtures they replace (assuming no further improvement in these devices over the next 30 years).
In sum, over half of our potable water use will become 300% more efficient over the next 30 years.
But add this up: 0% of that savings is reflected in the Harris water projections for Dry Gulch.
Consider that these savings, in themselves and without any price increases for high-use customers, would amount — under PAWSD's own growth assumptions — to over 3,000 acre feet of water savings by 2043, leaving the entire PAWSD district with a demand of 6300 acre feet of demand, including a loss rate of 34%.
Should PAWSD construct a 12,500 acre-foot reservoir at Dry Gulch, total storage in 2043 would be 16,600 acre-feet of storage, or 260% of demand.
But what if we base future growth and water usage on more reasonable numbers for population growth and water demand?
If we base population growth on the Colorado Demographer’s Office prediction of uninterrupted 3% growth in population over the next 35 years, the PAWSD district almost triples in size from 7000 taps to almost 20,000. This would still make Archuleta the third fastest growing County in all of Colorado, a very ambitious assertion for a County which has lost perhaps 10% of its population over the past two years.
What would daily water use of each of these houses and businesses be in 2043, if usage has already fallen to 255 gallons per day in 2008?
Well, is it unreasonable to think that PAWSD could reduce water losses by half over the next 35 years? That would still leave the district losing 17% of all the water it treats. There is little reason to doubt, given the technical ability of PAWSD engineering staff —and commitment of a fraction of intended reservoir spending — that the district could reduce losses to the industry standard of 10% (this standard is very likely to be lowered over the next 35 years). But let’s assume 17% of all water treated is lost out the pipes.
This brings usage down to 211 gallons per day. Now let’s subtract the 10% savings that this initial Water Conservation Plan assumes over the next 10 years. The average home or business is now using 190 gallons per day.
Now, let’s do something unfair to PAWSD. The suggestion is insulting, really. Let’s assume that for the years 2018-2043, the district fails to conserve a single gallon more than they achieve by 2018. We assume that every one of the 103 conservation measures and programs considered in Appendix B of the report fails to conserve a single gallon. Districts across Colorado require aerated shower heads and faucets, low water grasses and professionally installed lawn irrigation systems, whole house audits and leak detection. These districts create low-use and high-use tiers and peak week pricing for second homeowners which both reduce overall usage and generate revenue to fund their conservation programs. These districts achieve another 25% gain in conservation.
I am sorry to have suggested that PAWSD would fail to accomplish any further conservation. It is insulting to the professionalism of the PAWSD staff, who I expect will conserve another 1% per year over the next 25 years. But let’s assume all the district’s efforts are inept (Steve Harris’s water demand projections do). How much water would the 19,600 taps within the PAWSD district consume in 2043 if only these minimal improvements in water delivery and conservation are accomplished?
Total water usage by PAWSD customers in 2043 would then be about 4,175 acre-feet of water per year, or the approximate amount of water the district will have in its reservoirs at the end of this year.
Or about 12% of the water contained within a 35,000 acre-foot reservoir.
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