Back in early 2008,
David O. Powell, P.E., a Cal-Tech grad and former head of the San Diego Office
of the State Department of Water Resources and former Chief Engineer of Bookman
Edmonston Engineering, wrote a formal letter in response to the City of
Pasadena Groundwater Management Plan EIR - see Pasadena's Water Fall - Raymond Basin in Jeopardy"
http://pasadenasubrosa.typepad.com/pasadena_sub_rosa/2009/05/pasadenas-water-fall-raymond-basin-in-jeopardy.html
Powell’s concern was
that Pasadena was going to deplete the Raymond Basin by its water conservation
ordinance by reducing groundwater recharge from watering lawns and vegetation
on residential properties.
In 2009 David Powell appeared before the Pasadena City Council and testified that the City’s Water Conservation Ordinance had negative impacts on the Raymond Basin. The City of Pasadena trotted out Tim Brick, Chairman of the Board of MWD, to refute and apparently dismiss the claim citing the emergency of the statewide drought.
By mid 2009, the whole issue of negative environmental impacts of water conservation ordinances had received state and national attention on water blogs due to David Powell originally raising the issue in Pasadena – read here: http://www.inkstain.net/fleck/?p=3737
Now the City of Pasadena has apparently concocted a legal fiction about its prior claim of no impact from its water conservation ordinance. On the March 15 City Council Agenda (Item 7) Pasadena Planning staff recommend a negative declaration as to any impacts of the Water Conservation Ordinance on groundwater supplies. The specious grounds on which the City bases its Negative Declaration is that if the Raymond Basin Watermaster does not credit the City of Pasadena with groundwater recharge due to landscape irrigation then the impacts must be minimal. In other words, it does not matter what the estimated actual impacts might be under CEQA but whether the city gets credits from a water banker for groundwater recharge for home watering of landscaping. By analogy, "so even if you flew a million air miles, but you earned no 'frequent flyer mile' credits, it thus is deduced that you never traveled in an airplane." This must be an example of what might be called 'water logic' and why they say water runs uphill toward money.
So I asked David Powell if he would comment as to whether the effect of the City of Pasadena’s water conservation ordinance on the Raymond Basin was “minimal” as the city claims. Below is Dave Powell’s email response to me. Powell estimates that the loss to the Raymond Basin from not watering home lawns and greenery is 6,000 to 8,000 acre feet of water per year (or enough water for 30,000 to 40,000 people per year). That is an awful big “drop in the bucket” for the City to claim it is “minimal.” To give you an idea of the magnitude of 6,000 to 8,000 acre feet of water, the normal capacity of Devil’s Gate Dam and Reservoir in Pasadena is 2,600 acre feet.
RESPONSE BY DAVID O. POWELL VIA EMAIL:
A draft environmental Initial Study was prepared for the proposed Ordinance (Attachment B). The 20-day period to receive comments from the public began on February 8, 2010. Staff recommends adoption of a Negative Declaration for the code amendments. The potential of the Ordinance to impact the City's groundwater supplies and groundwater recharge was thoroughly analyzed. The Ordinance would not involve installation of any groundwater wells, and would not otherwise directly withdraw any groundwater. In time, the water used to irrigate landscape percolates to the groundwater basin, thereby recharging the basin (emphasis added). According to Geoscience Support Services, Inc. in their Baseline Ground Water Assessment Report of the Raymond Basin dated February 2, 2004:
With a reduction in volume of water being irrigated, less groundwater recharge is occurring in the long-term. Although the exact number of properties subject to the Water Efficient Landscape Ordinance not possible to determine, the number is limited. The return flow from applied waters is approximately 10 to 12 percent of those limited qualified properties. However, since the Raymond Basin Watermaster considers recharge from current levels of landscape irrigation throughout the City to be minimal, to the extent that the City does not receive any credit for such recharge, a reduction in recharge will not affect the Watermaster's analysis. Therefore, the overall effect on groundwater recharge reduction is less than significant.
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Apparently the City finally figured out that what we tried to tell them some time ago was valid. But they still managed to screw it up. It is my recollection of the Geoscience report that the 10 to 12 percent figure was to be applied to the entire amount of water delivered to consumers, not just that portion used for landscape irrigation.
In my view there is also an error in Geoscience's figure of 10 to 12 percent. Geoscience is an organization with very good credentials in the field of ground water modeling. But unfortunately I don't think they are so well versed when it comes to operation of distribution systems. So they erroneously considered that distribution system "unaccounted-for" water is largely made up of leakage from pipes. It's rather complicated, so I won't go into details. But trust me, my concerns are valid. I might also point out that these matters are matters which I covered in my comments on the EIR for the Raymond Basin conjunctive use plan.
So, all in all, I would make an educated guess (without spending a bunch of time making a detailed calculation) that the amount of contribution to groundwater under pre-drought restriction conditions might be on the order of 6-8 thousand acre-feet per year. Hardly a "less than significant amount".
Regards
Dave
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