Loading...
HomeMy WebLinkAbout10 - Grand Canal Dredging Project Phase 2 — Update on Contract No. 8171-2 (16H12)Q SEW Pp�T CITY OF �m z NEWPORT BEACH c�<,FORN'P City Council Staff Report March 12, 2019 Agenda Item No. 10 TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL FROM: David A. Webb, Public Works Director - 949-644-3311, dawebb@newportbeachca.gov PREPARED BY: Kathryne Cho, Civil Engineer, kcho(@newportbeachca.gov PHONE: 949-644-3014 TITLE: Grand Canal Dredging Project Phase 2 — Update on Contract No. 8171-2 (16H12) ABSTRACT - On October 23, 2018, City Council awarded Contract No. 8171-2 to Associated Pacific Constructors, Inc. (APC) for dredging the Grand Canal (north of the Park Avenue bridge) and both sides of the Harbor Island bridge. Due to unforeseen reduction in dredge quantities, staff would like to provide a project update and obtain approval for additional work to be performed under the same contract. RECOMMENDATION: a) Find this project exempt from the California Environmental Quality Act (CEQA) pursuant to Class 4 Section 15304(g) (Maintenance dredging where the spoil is deposited in a spoil area authorized by all applicable state and federal regulatory agencies) of the CEQA Guidelines, because this action will not result in a physical change to the environment, directly or indirectly; b) Accept the project update as presented herein; c) Authorize staff to proceed with additional maintenance work in the Grand Canal under the same contract; and d) Authorize staff to include dredging within the commercial marina at 2241 W. Coast Highway, as well as other nuisance high spots within the Newport Harbor. FUNDING REQUIREMENTS: The approved Contract No. 8171-2 includes sufficient funding for this project. 10-1 Grand Canal Dredging Project Phase 2 — Update on Contract No. 8171-2 (16H12) March 12, 2019 Page 2 DISCUSSION: A depth survey of the entire canal from several years ago was used to design and complete Phase 1 of dredging Grand Canal. Based on this information, the project scope for Phase 2 anticipated dredging approximately 7,300 cubic yards of material from the 10 -foot navigable area of the Grand Canal (down to the depth of 4). Upon completion of our contractors (APC) pre -dredge survey, it was determined that there was much less material to be dredged than previously anticipated and that the navigable area of the canal was largely at the design elevation. With this new information, APC was directed to only dredge the known problem areas that were above the target design depth which included the mouth of the canal and adjacent to the Park Avenue Bridge. Once completed, APC moved on to dredging the north and south sides of the Harbor Island Bridge as planned. While at this location, Harbor Island residents voiced concerns regarding the stability of the bridge. As a result, the dredge area at this location was modified and decreased to stay at least 10 -feet clear of the existing bridge piles. With much less work being performed and APC mobilized and available, staff took advantage of this opportunity to address another area of concern and rehabilitate a small beach on the peninsula along Edgewater Avenue between Anade Avenue and Medina Way (across from Bay Island) using the City's existing 2016 permit for this particular beach. APC spent four days moving sand from the low -tide line up to the high -tide line. To date, APC has satisfied their contractual obligation. Upon the quick completion of the Grand Canal work, a few residents raised concerns and requested additional Grand Canal dredging maintenance items be included in the project. Staff met with the residents at the project site to answer questions and understand the concerns. Three years ago, coarse beach sand was imported into the Grand Canal and placed up against the seawalls to help maintain their structural integrity. This imported material has since migrated away from the seawall and moved lower down the beach profile and toward the navigable area. Residents requests the City reshape the beaches and bring this material back up against the seawall as part of the current project. With the lower contract cost due to the difference between the bid quantities versus actual dredged quantities, staff requests Council approval to work with APC to perform additional dredging maintenance work in the Grand Canal to address this goal. Staff proposes to move sand from the low -tide line to the high -tide line along the seawall with water and land-based equipment, thereby heightening the useable beach sand as well as helping to provide additional support along the seawall where possible. Aside from this extra dredging work being requested in the Grand Canal, there is also an immediate need for additional dredging within a private commercial marina located at 2241 West Coast Highway. This is a result of the recent heavy rain events coupled with the failure of a City storm drain pipe that crosses West Coast Highway within Mariners Mile that deposited a significant amount of material at the storm drain outlet that discharges into this marina area. The storm drain pipe has now been repaired and a structural liner has been installed. 10-2 Grand Canal Dredging Project Phase 2 — Update on Contract No. 8171-2 (16H12) March 12, 2019 Page 3 Staff requests Council approval to include this additional work to dredge approximately 70 cubic yards of material within the marina into the current APC contract. Project design is still being formulated, but staff anticipates this work to cost between $50,000 to $70,000. Additionally, staff identified a couple of other nuisance high spots within the Newport Harbor that APC could assist with if funding allows. With the aforementioned scope reduction with the original Grand Canal work, there is sufficient funding to cover this additional requested work. ENVIRONMENTAL REVIEW: Staff recommends the City Council find this project exempt from the California Environmental Quality Act (CEQA) pursuant to Class 4 Section 15304(g) (Maintenance dredging where the spoil is deposited in a spoil area authorized by all applicable state and federal regulatory agencies) of the CEQA Guidelines, California Code of Regulations, Title 14, Chapter 3, because this action will not result in a physical change to the environment, directly or indirectly. NOTICING: The agenda item has been noticed according to the Brown Act (72 hours in advance of the meeting at which the City Council considers the item). ATTACHMENT: Attachment A — Location Map 10-3 CITY OF COSTA MESA Q 0 17TI )TH S JOHN WAYNE AIRPORT �qc�F/c OCF-4/V ] COMPLETED PROJECT LOCATIONS •• PROPOSED PROJECT LOCATIONS VICINITY MAP NOT TO SCALE GRAND CANAL DREDGING PROJECT PHASE 2 LOCATION MAP - O�p CITY OF IRVINE P� UNIVERSITY Attachment SEW, CITY OF NEWPORT BEACH PUBLIC WORKS DEPARTMENT C-8171-2 1 03/12/19 10-4