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HomeMy WebLinkAbout930 Via Lido Nord Bulkhead-Seawall Conditions Report Revised on 01-06-20 P M A C O N S U L T I N G , I N C . CONSULTING STRUCTURAL ENGINEERS 28161 Casitas Ct. PH. (714) 717-7542 Laguna Niguel, CA 92677 e-mail: p.petrov@pma-bg.com January 06, 2020 Richard W. Barrett 930 Via Lido Nord Newport Beach, CA 92663 BULKHEAD/SEAWALL CONDITIONS REPORT Richard W. Barrett; Applicant 930 Via Lido Nord City of Newport Beach, County of Orange PMA Job #24918-1 Dear Mr. Barrett, PMA Consulting, Inc. is pleased to provide this report in accordance with Section 21.30.15.E.3 of City of Newport Beach Municipal Code. STATEMENT OF THE PREPARER’S QUALIFICATIONS Plamen Petrov, P.E., the preparer of this report, holds a Master of Science in Structural Engineering from University of Architecture, Structural Engineering & Geodesy of Sofia, Bulgaria, and is a Licensed Civil Engineer by the State of California Certificate No. C66947. For the last 19 years of his professional career he has been actively involved in the design and entitlement of many Waterfront Developments such as custom homes, seawalls, piers, platforms, floating docks and marinas. A great number of Bulkhead Condition Reports prepared by him have been reviewed and accepted/approved by California Coastal Commission. All the above being said, Plamen Petrov, P.E. shall be considered a qualified preparer for the Bulkhead/Seawall Conditions Report on this project. OBSERVATIONS Cursory observations of the existing seawalls were conducted by a representative of our office on June 27, 2018 and on August 29, 2019. Observed were the visible/exposed portion of the waterfront face of the upper seawall, waterfront face of the lower seawall and partially exposed concrete buttress walls of lower seawall. FINDINGS The cast-in-place concrete seawalls were found in a generally good condition, without evidences of distress or instability, except for a few repairable cracks on lower seawall. The strength and stability of the lower seawall is provided by concrete buttress walls in direction perpendicular to the seawall. Such seawall assembly doesn’t need, thus doesn’t have tiebacks. The absence of coping at the upper seawall, and the existence of pool behind it gives us the base to assume that it has been constructed as a typical retaining wall consisting of concrete footing placed underneath the pool, and cast-in-place concrete stem wall on top of footing, without tiebacks. CONCLUSION Based on the cursory visual observations we conclude that the existing seawalls are required to protect the principal structure and site improvements on the lot, the adjacent properties, public facilities and infrastructure; thus, they can’t be removed. Removal of the seawalls will result in erosion and undermining the foundations of the structures and site walls at the subject site and both adjacent sites. Top of Lower Seawall Elevation at +7.17’NAVD88 is below the minimum required top of seawall elevation of +10.0’MLLW per City of Newport Beach Standards, but top of Upper Seawall Elevation at +11.7’NAVD88 is above it. Since the two seawalls are considered to act/perform as one protective devise for this property, together they shall be considered as meeting the current City of Newport Beach Standards in terms of height. Once the existing lower seawall is raised in compliance with the enclosed drawings SW-1 thru SW-3, need for a new shoreline protective devise is not anticipated over the economic life of the existing development to protect it from flooding, wave runup or erosion. If found not adequate for the actual sea level rise over the next 75 years, the existing seawalls assemblies allow to be increased in height per the enclosed STD-601-L without further seaward encroachment. If during this period the seawalls displays any sign of distress that requires immediate attention, they should be repaired or replaced at that time accordingly, without seaward encroachment from its current location. The above conclusion was prepared based on the existing conditions, proposed drawings, current projection of future Sea-Level Rise, and within the inherent limitations of this study, in accordance with generally acceptable engineering principles and practices. We make no further warranty, either expressed or implied. PMA Consulting, Inc. appreciates the opportunity to work with you towards the successful completion of your project. Should you have any questions regarding this report, please contact us. any questions regarding this report, please give us a call. Respectfully submitted, Plamen Petrov, P.E. Principal Enclosures: Seawall DWGS SW-1 thru SW-3 STD-601-L