ITEM:   CONSENT CALENDAR

 

4.

CONSIDER AUTHORIZATION OF FUNDS TO PURCHASE IRRIGATION EQUIPMENT TO MITIGATE IMPACTS OF PUMPING FROM LOWER CARMEL VALLEY WELLS

 

Meeting Date:

July 21, 2008

Budgeted: 

Yes

 

From:

Darby Fuerst,

Program/

2-1-1.A

 

General Manager

Line Item No.:

 

Prepared By:

Thomas Christensen

Cost Estimate:

$6,647

 

General Counsel Approval:  N/A

Committee Recommendation:  The Administrative Committee reviewed this item on

July 15, 2008 and recommended approval.

CEQA Compliance:  N/A

 

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 4-A). With tax included the cost will be approximately $6,650.  Previous estimates for this kind of irrigation equipment purchased new were in excess of $10,000.

 

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 15, 2008 and voted 3-0 to recommend approval. 

 

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 where 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 the protecting riparian vegetation in the area of four Lower Carmel Valley wells owned by CAW.  Funds are under Program 2-1-1-A, Riparian Mitigations, Irrigation Program, “Operate and maintain 4-well system” (Account No. 4-03-7850.11, $7,000).  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

4-A      Rain for Rent Sales Estimate

 

 

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