ITEM:

CONSENT CALENDAR

 

3.

CONSIDER EXPENDITURE OF FUNDS TO RETAIN SCHAAF AND WHEELER CONSULTING CIVIL ENGINEERS TO EVALUATE THE RECLAMATION DITCH AS A SOURCE OF SUPPLY FOR THE GROUNDWATER REPLENISHMENT PROJECT

 

Meeting Date:

October 21, 2013

Budgeted:

Yes

 

From:

David J. Stoldt,

Program/

Augment Water Supply

 

General Manager

Line Item No.:

1-5-1 / 5-7860.10

 

Prepared By:

Larry Hampson

Cost Estimate:

$ 40,000

 

General Counsel Review: N/A

Committee Recommendation: The Administrative Committee reviewed this item on October 14, 2013 and recommended approval by a vote of 3-0.

CEQA Compliance: N/A

 

SUMMARY: The Monterey Regional Water Pollution Control Agency (MRWPCA) and the District (MPWMD) are working cooperatively to develop the Monterey Peninsula Groundwater Replenishment (GWR) Project to provide highly treated water from an advanced water treatment plant to the Seaside Groundwater Basin for indirect potable use in the California American Water supply system for the Monterey Peninsula. Potential source waters for the project include winter stormwater runoff into Lake El Estero in Monterey, City of Salinas treatment plant water, stormwater runoff from an urbanized basin on the south side of Salinas, wastewater from the MRWPCA Regional Treatment Plant, and flow diversions in the Reclamation Ditch west of Salinas. Each of these potential sources will be evaluated in accordance with the California Environmental Quality Act in an Environmental Impact Report (EIR). Diversion of flow from the Reclamation Ditch has potential environmental benefits to downstream sensitive habitats by removing a portion of the pollutant load in the stream.

 

MPWMD staff propose to retain Schaaf and Wheeler, Consulting Civil Engineers, to conduct a hydrologic analysis of flow in the Reclamation Ditch watershed and to study the potential to divert a portion of the flow near the Davis Road overcrossing into the sanitary sewer collection system (see Exhibit 3-A). A scope of work is attached as Exhibit 3-B (Note: Task 4 will be deleted). Transfers of source water flowing in known and definite channels, such as the Reclamation Ditch, to the GWR Project would be a consumptive use that may require an appropriative permit from the State Water Resources Control Board (SWRCB).

 

MPWMD desires to retain a qualified consultant to provide hydrologic information that may be used in the GWR Project EIR and for a permit application to the SWRCB. Tasks include analysis of Reclamation Ditch watershed flows, potential downstream changes due to diversions, and an identification of capacity in the existing wastewater collection system to accept additional flow. MPWMD staff will coordinate project work with MRWPCA, City of Salinas, and others as necessary. Work is expected to take about three months, including reviews by interested agencies.

 

RECOMMENDATION: Staff recommends approval of the expenditure of up to $40,000 in budgeted funds for analysis of flow availability for diversion from the Reclamation Ditch near Davis Road to supply a portion of the source water for the Monterey Regional Water Pollution Control Agency Groundwater Replenishment Project. The Administrative Committee considered this matter at their October 14, 2013 meeting and voted 3 to 0 to approve the expenditure. If this item is adopted with the Consent Calendar, the General Manager would be authorized to enter into an agreement for services with Schaaf and Wheeler Consulting Civil Engineers for $37,580, with a contingency of an additional $2,420 for a total not-to-exceed of $40,000. It is expected that these costs will be included in the overall GWR budget and MPWMDs share will be 75%.

 

IMPACTS TO STAFF/RESOURCES: Funds for this work are identified in the proposed FY 2013-14 Budget, Program Line Item 1-5-1, Augment Water Supply Groundwater Replenishment Project. The proposal from Schaaf and Wheeler, Consulting Civil Engineers anticipates expenses of $37,580, which does not include funds for Task 4, Identify Water Quality Limitations (this task will being carried out by MRWPCA). The difference between the proposal and staff recommendation is $2,420, which allows for a 6% contingency.

 

BACKGROUND: The Reclamation Ditch drains a 157 square-mile area that includes headlands, agricultural areas, the City of Salinas, the Castroville area, and a part of Prunedale (see Exhibit 3-B). The Ditch, created between 1917 and 1920, is a network of excavated earthen channels used to drain surface runoff generated in the watershed. Early maps of the watershed[1] show that much of the present-day channel was covered by a chain of shallow lakes that drained into Tembladero Slough and into Moss Landing Lagoon (now Moss Landing Harbor). Currently, the Reclamation Ditch is a major drainage channel that flows from east to west through Salinas and continues west where it drains into Tembladero Slough, then into the Old Salinas River Channel, and ultimately into Moss Landing Harbor through the Potrero Tide Gates.

The Reclamation Ditch is virtually perennial west of the City of Salinas at a point downstream of agricultural and urban development. According to USGS estimates, flow west of Salinas at the San Jon Road gage (about two miles downstream of Davis Road) ceased on only three days between 1971 and 1985, and on those days, standing water was probably still present throughout most of remainder of the Reclamation Ditch. The presence of standing water is reflective of historical conditions, since the area was a system of lakes. However, the presence of dry-season flow is a consequence of dry-season urban discharges and agricultural tailwater. Annual runoff at the USGS gage station at San Jon Road (drainage area of 106.5 square miles) for Water Years 1971-2012 has averaged 11,220 AFA.

 

Schaaf and Wheeler Consulting Civil Engineers have previously prepared studies and models of the Reclamation Ditch for the Monterey County Water Resources Agency and are familiar with the Reclamation Ditch system and its interactions with Tembladero Slough and the Salinas River.

 

EXHIBIT

3-A Reclamation Ditch watershed map

3-B Schaaf and Wheeler Consulting Civil Engineers Proposal for Services: Evaluation of the Reclamation Ditch as a source of supply for the Groundwater Recharge Project

 

 

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[1] See Figures 2.2 and 2.9, Final Report: Monterey County Water Resources Agency - Reclamation Ditch Watershed Assessment and Management Strategy: Part A - Watershed Assessment, The Watershed Institute, Division of Science and Environmental Policy, California State University Monterey Bay,