HomeMy WebLinkAboutItem 06 - Laguna Lake 2020 Maintenance Dredging
Department Name: Public Works
Cost Center: 5002
For Agenda of: January 14, 2020
Placement: Consent
Estimated Time: N/A
FROM: Shelly Stanwyck, Assistant City Manager, Community Services & Interim Public
Works Director
Prepared By: Richard Burde, Engineer III
SUBJECT: LAGUNA LAKE 2020 MAINTENANCE DREDGING PROJECT,
SPECIFICATION NO. 91392
RECOMMENDATION
1. Approve the Project Plans and Special Provisions (to be transmitted as agenda
correspondence prior to meeting) for the Laguna Lake 2020 Maintenance Dredging Project;
and,
2. Authorize staff to advertise for bids; and,
3. Authorize the City Manager to award the construction contract if the lowest responsible bid
is within the Engineer’s Estimate of $380,000.
DISCUSSION
Background
The City of San Luis Obispo owns the 344-acre Laguna Lake Natural Reserve that includes most
of Laguna Lake, portions of Prefumo Creek and its outlet into the Lake, and adjacent upland
areas. In July of 2014, Council adopted the “Laguna Lake Natural Reserve Conservation Plan”
which outlined future management and conservation goals for Laguna Lake. On January 19,
2016, Council authorized MNS Engineers to produce construction documents for dredging of the
Lake. Also approved at this time were the Plans and Specifications and regulatory permit
applications to the Army Corp of Engineers, the California Department of Fish and Wildlife, and
the Regional Water Quality Control Board.
The scope of work for the Laguna Lake 2020 Maintenance Dredging Project will be to remove
2,000 cubic yards (CY) of accumulated sediment at the mouth of the Prefumo Creek which
discharges into the Lake from the south. In addition to this dredging operation, the project
includes approximately 90 linear feet (LF) of bank stabilization at the Lake’s main parking lot.
This will prevent further deterioration of the bank and prevent asphalt from eroding into the
Lake.
Although the permits received allow for up to 4,000 CY of annual sediment removal, City staff is
recommending limiting the total volume in the first year to 2,000 CY to determine the benefits of
this methodology with the intent of increasing volumes in subsequent years. The nature of this
project is highly logistical, and staff intend to use the first year’s dredging efforts to refine the
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work and increase efficiencies moving forward. Essentially, the project is a pilot and staff
expects to learn from it and leverage this knowledge for future phases of dredging.
All necessary permits from governing environmental agencies to commence the dredging
operation have been obtained. Permitting agencies include Army Corp of Engineers, California
Department of Fish and Wildlife, and the California Water Control Board. These permits are
valid for a five-year period, starting in August of 2019, and have an option for a one-time
extension of five additional years.
Fresh water lake dredging work is a highly specialized in nature, and contractors that perform
this work are not commonly available in this area. For this reason, the bidding period for this
project is longer than typical with the hope of attracting multiple competitive bids from qualified
contractors.
Previous Council or Advisory Body Action
This project was originally identified in the 2015-17 Financial Plan that was approved by
Council. Subsequently, funding was appropriated in the 17-19 and 19-21 Financial Plans.
In addition to the above budget adoptions, Council took the following actions:
➢ August 18, 2015 – Authorize the issuance of a Request for Proposals (RFP) for phase I
of the Laguna Lake Dredging and Sediment Management Project in furtherance of the
City’s Laguna Lake Natural Reserve Conservation Plan
➢ January 19, 2015 – Award and approve a consultant services agreement with the firm
MNS Engineers, Inc. (“MNS”) in an amount not-to-exceed $445,000 for Laguna Lake
Dredging and Sediment Management
➢ September 20, 2016 - Receive and file the Preliminary Dredging Report (the “PDR”)
prepared by MNS Engineers, Inc. and, as further described in the PDR, direct staff to
proceed with further analysis and further recommendations.
➢ October 24, 2017 – Approve a Resolution to adopt a Mitigated Negative Declaration of
Environmental Impacts for the Laguna Lake Dredging and Sediment Management
Project.
➢ May 8, 2019 – The City of San Luis Obispo received the California State Fish and
Wildlife 1600 Lake Alteration Agreement, permitting the alteration of the Lake’s bed.
➢ August 7, 2019 – The City of San Luis Obispo received the Army Corp of Engineers 404
permit allowing for the discharge of dredged material into the waters of the United States.
➢ September 11, 2019 – The City of San Luis Obispo received the 401 permit from the
California Water Control Board, which expands on the 404 permit received from the
Army Corp by outlining water quality guidelines that must be maintained during
construction.
Policy Context
Per the October 2018 Purchasing Policy Update to the July 2015 Financial Management Manual,
Council approval is required for Public Projects that cost over $175,000.
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Public Engagement
Public engagement was done during the initial identification of this project to be included in the
2017-19 Financial Plan and again during preparation of the construction documents.
In addition, a neighborhood organization referred to as “The Friends of Laguna Lake” has
continued to communicate with, and receive progress updates from, City staff. During this time
“The Friends of Laguna Lake” have acted as liaison between the City and community
stakeholders by providing progress updates regarding permitting, design, and construction
timelines. City staff anticipates that this level of communication will continue throughout the life
of the project.
CONCURRENCE
The Administration and Parks and Recreation departments concur with the proposed
recommendation outlined in this document.
ENVIRONMENTAL REVIEW
Council approved a Mitigated Negative Declaration for the project on October 24, 2017. All
environmental mitigations have been outlined in the permits that have been issued by the Army
Corp., California Water Board, and Department of Fish and Wildlife. No additional
environmental review is required.
FISCAL IMPACT
Budgeted: Yes Budget Year: 2019-20 and 2020-21
Funding Identified: Yes
Fiscal Analysis:
Funding Sources Current FY Cost
Annualized
On-going Cost
Total Project
Cost
General Fund $496,500 $496,500
State
Federal
Fees
Other:
Total $496,500 $496,500
Funding for Laguna Lake
Dredging
2019-20 2020-21
$150,000 $350,000
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Engineer's Estimate $380,000
Conginencies (20%)$76,000
Monitoring Services $20,000
Water Quality Sampling $20,000
Printing $500
TOTAL PROJECT $496,500
Budget Available (91392)$500,000
Budget Remaining $3,500
Laguna Lake Maintenance Dredging Project
Engineer’s estimate for the work is $380,000. Contingencies, environmental monitoring, and
water quality sampling are estimated to be $76,000, $20,000, and $20,000 respectively. The
2019 fiscal year allocated $150,000 to dredging effort, and an additional $350,000 will be made
available at the start of the 2020 fiscal year. This brings the total budget for project completion to
$500,000) to complete the summer 2020 dredging efforts. Any remaining funds could be added
to the dredging efforts scheduled for the summer of 2021.
ALTERNATIVES
Council could choose to not authorize City staff to advertise the dredging of Laguna Lake. This
is not recommended since sediment will continue to accumulate, requiring more frequent or
larger more costly dredging operations in the future. Additionally, dredging the Lake has been
identified as an “Other Important Council Objective”.
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