ADMINISTRATIVE
COMMITTEE |
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2. |
CONSIDER
EXPENDITURE OF BUDGETED FUNDS TO PURCHASE IRRIGATION EQUIPMENT TO MITIGATE
IMPACTS OF PUMPING FROM LOWER CARMEL VALLEY WELLS |
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Meeting Date: |
July 16, 2008 |
Budgeted: |
Yes |
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From: |
Darby Fuerst, |
Program/ |
2-1-1.A |
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General
Manager |
Line
Item No.: |
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Prepared By: |
Thomas
Christensen |
Cost Estimate:
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$6,647 |
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General Counsel Approval: N/A
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Committee
Recommendation: The Administrative Committee reviewed this
item on
July 16, 2008 and recommended ________________.
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CEQA Compliance: N/A |
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SUMMARY: The District
has irrigated riparian vegetation in the vicinity of California American
Water’s (CAW) San Carlos and Cañada Wells since 1988 (except for the 1995 and
1998 El Niño years and in 2003) to mitigate the effects of groundwater
pumping. Over the years, several
irrigation techniques including drip irrigation have been used. However, for this particular site, a
temporary overhead sprinkler irrigation system has been found to be the most
successful method. This system has been
rented over the years for a cost of around $2,600 per season. Foreseeing the
need to rent this equipment year after year, District staff requested a quote
to buy this used equipment. Rain for Rent provided an estimate for purchase of
this equipment for $6,197 without tax (Exhibit 2-A). With tax included, the cost
will be approximately $6,650.
RECOMMENDATION: Authorize the General Manager to purchase irrigation
equipment from Rain for Rent at a cost not to exceed $6,650. If approved, this item will be adopted
along with the Consent Calendar. The Administrative Committee reviewed this item on
July 16, 2008 and recommended ______________.
BACKGROUND: The District operates nine irrigation systems
in Carmel Valley to mitigate for surface and ground water diversions during the
dry season. The riparian corridor has responded favorably with additional
growth and diversity, contributing to channel stability and enhancing riparian
habitat.
For the area of CAW’s Cañada and San
Carlos Wells, sprinkler irrigation has been found to be the most successful
method. Portable aluminum laterals with
impact sprinkler heads on four-foot risers are placed along the toe of the
bank, and the risers allow irrigation of the banks. This method is used in place of drip irrigation
because the vegetation in this area has become very dense, and replacing
clogged emitters and performing annual maintenance of a drip system has become
too hazardous and difficult. The water
use for the Cañada-San Carlos area has averaged approximately three acre-feet
per year.
The District has used the sprinkler
method in most years since 1999, renting equipment from Rain for Rent. Equipment was not rented in years when there
was adequate groundwater in this reach as evidenced by standing pools of water
throughout the irrigation season (e.g., during the 1995 and 1998 El Niño years
and in 2003). However, ground water
pumping has increased in the lower Carmel Valley pursuant to direction by the
State Water Resources Control Board and a Conservation Agreement between CAW
and the National Marine Fisheries Service.
When groundwater levels drop, it is critical to irrigate riparian
vegetation to maintain its health and vigor.
If the Cañada–San Carlos Wells area were not irrigated this year, the
vegetation could die, leading to loss of prime riparian habitat and bank
instability.
Rain for Rent was chosen because of
their location and price in comparison with other irrigation equipment
suppliers. The business office is in
South Salinas, and they have equipment storage sites throughout the
county. The other primary source for
District irrigation equipment and supplies, Martin’s Irrigation Supply, has an
office in Sand City, but they do not carry the type of equipment needed for the
Cañada-San Carlos Irrigation System. The
District’s experience with Rain for Rent’s service and equipment has been
excellent.
IMPACTS ON STAFF AND RESOURCES: The Fiscal Year 2008-2009 budget includes
funds to operate and maintain irrigation equipment for protecting riparian
vegetation in the area of four Lower Carmel Valley wells owned by CAW. Funds are available to purchase irrigation
equipment under Program 2-1-1-A, Riparian Mitigations, Irrigation Program,
“Operate and maintain 4-well system” (Account No. 4-03-7850.11, $7,000). In addition, CAW pays the District $7,000 per
year as a contribution to the maintenance and operation of irrigation systems
for riparian vegetation in the area of CAW’s four Lower Carmel Valley wells
(Cañada, San Carlos, Cypress, and Pearce).
Water is supplied by CAW at no cost to the District for irrigation in
the four-well area. The cost of leasing
equipment to irrigate for the area influenced by the San Carlos and Cañada
Wells is estimated at approximately $2,600 per year. It is evident that 2008 had a dry spring,
with river flows well below the levels during wet years. We anticipate that pumping by CAW and others
from Lower Carmel Valley will cause the groundwater levels to decline below the
root zone of riparian vegetation. Installation and operation of the systems
will be performed under the direction of the District’s Riparian Projects
Coordinator.
EXHIBIT
2-A Rain for Rent
Sales Estimate
U:\staff\word\committees\Admin\2008\20080716\02\item2.doc