Item No. 8
Town of Atherton
CITY COUNCIL STAFF REPORT – REGULAR AGENDA
TO: HONORABLE MAYOR AND CITY COUNCIL
GEORGE RODERICKS, CITY MANAGER
FROM: ROBERT OVADIA, PUBLIC WORKS DIRECTOR
DATE: JULY 15, 2026
SUBJECT: REPORT ON THE UPPER ATHERTON CHANNEL
STABILIZATION PROJECT AND APPROVAL OF
AMENDMENTS TO AGREEMENTS FOR DESIGN AND PROJECT
MANAGEMENT
RECOMMENDATION
It is recommended that the Council receive an update on the Upper Atherton Channel Stabilization Project and approve amendments to the professional services agreements with Tetra Tech, Inc. for additional Design, Cultural Resource, Environmental and Regulatory support services that will be necessary to meet the requirements of the Permitting Agencies for the Upper Atherton Channel Stabilization Project, and approve an amendment with Capital Program Management, Inc. for additional project management support through September 2027.
BACKGROUND
The City Council approved a professional services agreement with Tetra Tech, Inc. on July 14, 2024, to develop potential channel repair solutions for Atherton Channel west of Alameda de las Pulgas.
In January 2025, Tetra Tech presented to the Town Council a conceptual plan with potential repairs for the various conditions found in the Atherton Channel. Those proposed solutions were further refined and discussed in preliminary meetings with various Permitting Agencies, including the Army Corps of Engineers (USACE) and the Regional Water Quality Control Board (RWQCB).
Both Agencies have now provided initial feedback on their desired design solutions and the formal permitting process that will be required. The feedback received will requrie additional design and project management requirements.
ANALYSIS
Upper Atherton Channel Stabilization Project
JULY 15, 2026
A series of initial meetings were held with the USACE and then with the RWQCB to get their initial reactions to the conceptual design options and layouts to gauge their potential for approval by the permitting agencies. The conceptual designs presented and to the Permitting Agencies included the following proposed design options:
• Riprap lower portion of the sides + Grading the Slopes • 3’ Tall Retaining Wall and Bench
• 3’ Retaining Wall + Bench + Regrading the Slopes
A wetland delineation report was submitted and the team requested that the ACOE review be conducted under a Nationwide Permit Application.
Following the consultations, the Permitting Agencies advised that the designs should be adjusted to allow for softer and more green/natural solutions. One of the solutions requested by the regulatory agencies was to re-grade the slope embankments to a flatter slope and replanting with native planting. This would require expanding the channel width, encroaching significantly into the adjacent resident properties, requiring new expanded easements for channel construction and maintenance. A sampling of residents were consulted on the feasibility of expanding the channel into their properties and though some were agreeable to a partial layback above an embankment wall, the consensus was that a slope layback would not be a desired solution. The conceptual designs were again revised according to the feedback received from residents and permitting agencies, seeking to find an acceptable middle ground between the Permitting Agencies requests and residents desires and needs.
This round of updated solutions were then presented in another joint meeting with USACE and the RWQCB. In this meeting, the permitting agencies advised on their requirements and expectations for the project. These requirements will have a significant impact to the project and include the following:
• Project improvements will require an “individual permit” rather than coverage under Nation Wide Permits, which have much more stringent requirements. • The linear foot estimate of needed mitigation measures was increased from approximately 1,000 lineal feet to spot locations to more contiguous segments totaling 2,250 lineal feet. • Repairing/replacing of certain existing structures in-kind will not be permitted, as the structures are no longer permittable by the agencies. New structures will be required and would be permitted as such.
• The Clean Water Act Section 401 certification required. • The Clean Water Act Section 404 permit required.
• USACE and the RWQCB prefer that greener options be explored, requiring additional studies.
• Environmental Assessment will be subject to National Environmental Policy Act (NEPA) requirements in addition to the California Environmental Quality Act (CEQA) requirements.
• Cultural Resources evaluation required for NEPA review.
Upper Atherton Channel Stabilization Project
JULY 15, 2026
• Mitigation will be required for impacted areas – note that there is insufficient area available for on-site mitigation.
These requirements from the Permitting Agencies will significantly increase design costs, construction costs, agency costs and management costs.
• Increase in Design Costs - Tetra Tech $681,207 (current contract is $746,378). New total Contract Cost would be $1,427,585. The amendment would include the following items:
o Tetra Tech Design Management - $30,634
o Basis of Design Report - $67,174
o Cultural Resources Evaluation under NHPA Section 106 - $41,589 o Environmental Assessment - $168,992
o Alternatives Analysis - $26,428
o Functional Assessment and Mitigation Plan - $49,549
o Identifying and creating Temporary Construction Easements - $69,948 o Planting and Irrigation plans - $73,120
o Tetra Tech Bid Support - $14,164
o Tetra Tech Construction Support - $107,417
o Other Tasks - $32,192
• Increase in Project Management Costs – CPM (9-month extension of services) – Increase by $29,000 (current contract cost of $121,000). New total contract cost would be $150,000. • Agency Costs
o Estimated Permitting Fees - $13,000
• Other Estimated Costs
o Temporary Construction easements - $1,800,000
o Mitigation Bank Costs - $150,000
• Construction and Inspection
o Current Construction Estimate is $7,000,000
o Construction Management Services - $350,000 (estimated at 5%) o Testing and Special Inspections - $150,000
o Tribal Monitoring - $160,000
o USFW Wildlife Monitoring - $120,000
ESTIMATED SCHEDULE
The current project schedule based on the permitting requirements is as follows:
Upper Atherton Channel Stabilization Project
JULY 15, 2026
• Environmental Assessment submission – December 2026.
• Preliminary Permit Submittal Agencies – December 2026. • Permit Review by Agencies – March 2027
• 65% Construction Documents (CD’s) – April 2027
• 90% CD’s – July 2027
• 100% CD’s – August 2027
• Construction Anticipated in the Spring of 2028.
Staff is requesting approval of the Professional Services Agreements with Tetra Tech and CPM to provide the additional services required for design and environmental requirements outlined by the Permitting Agencies. If approved, Tetra Tech will prepare the newly required permitting documents and various applications for permitting review. As the design is furthered, Tetra Tech and CPM will continue to coordinate with the various regulatory agencies to obtain the needed approvals and permits required for the project. This process may alter the proposed methods of protection to meet the various regulatory agency requirements and will lead to a complete set of construction documents for a future construction project to implement the design. Updated cost estimates shall be provided at each milestone step along the way.
FISCAL IMPACT
Current impact to the Tetra Tech Contract is an additional $681,207 bringing the total contract cost to $1,427,585. Current Impact to the CPM Management contract is an additional $29,000 bringing the total contract cost to $150,000. Sufficient funds are available in the Capital Improvement Project for these additional services.
GOAL ALIGNMENT
This Report and its contents are in alignment with the following Council Policy Goals:
• Goal A - Preserve Small Town Character & Quality of Life • Goal E - Maintain and Improve Public Infrastructure
POLICY FOCUS
The Council’s policy focus should be on the need to maintain public infrastructure as well as implementing drainage improvement projects outlined in the Town’s Drainage Master Plan.
PUBLIC NOTICE
Public notification was achieved by posting the agenda, with this agenda item being listed, at least 72 hours prior to the meeting in print and electronically. Information about the project is also disseminated via the Town’s electronic News Flash and Atherton Online. There are approximately 1,200 subscribers to the Town’s electronic News Flash publications. Subscribers include residents as well as stakeholders –to include, but be not limited to, media outlets, school districts, Menlo Upper Atherton Channel Stabilization Project
JULY 15, 2026
Park Fire Protection District, service provides (water, power, and sewer), and regional elected officials.
COMMISSION/COMMITTEE FEEDBACK/REFERRAL
This item has not been before a Town Committee or Commission
ATTACHMENTS
1. Current Progress Plan Set
2. Tetra Tech Additional Services Proposal