HomeMy WebLinkAboutSDP 2023-0012; LEGOLAND CALIFORNIA PROJECT 2025; WATER QUALITY STUDY; 2023-08-02
Chang
Civil Engineering◦Hydrology◦Hydraulics◦Sedimentation
P.O. Box 9496 Rancho Santa Fe, CA 92067-4496 T: 858.692.0760
F: 858.832.1402
wayne@changconsultants.com
Memorandum
To: Adam Kooienga, Hofman Planning Associates
From: Wayne W. Chang
Re: LEGOLAND California Project 2025
Date: August 2, 2023
LEGOLAND California Project 25 proposes a “LEGO Galaxy” attraction within the existing
theme park. The project will cover approximately 2.38 acres and be located at the existing
“Driving School” and “Junior Driving School” attractions, which will be demolished and
removed. The major project components include a headline ride, secondary exterior ride,
playscape, and play area. The development also includes grading, utilities, hardscape, planting,
and retrofitting of existing recycled water irrigation systems. The grading plans, drainage report,
and storm water quality documentation are being prepared by Commercial Development
Resources.
Since the project will disturb over an acre and redevelops over 10,000 square feet of impervious
surface it is a Priority Development Project and subject to pollutant and flow control
requirements. It is also required to develop and implement a Construction Storm Water Pollution
Prevention Plan.
The SWPPP will incorporate construction best management practices during grading and
associated construction activities. The BMPs will reduce potential wind and water erosion during
grading activities to prevent the potential discharge of pollutants into receiving waters. All
development is subject to design review by the City of Carlsbad to ensure that the project would
comply with performance standards and design guidelines.
The project includes a storm water drainage system to prevent post-construction water quality
impacts to downstream receiving waters. Storm water runoff from LEGOLAND California is
currently conveyed to an existing regional BMP along the southerly edge of the LEGOLAND
parking lot. The regional BMP has excess pollutant and flow control capacity. REC Consultants,
Inc. performed analyses demonstrating adequacy of the regional BMP to treat the project’s
runoff.
The project’s storm water drainage system and water quality BMPs will be designed in
accordance with all applicable requirements including those set forth in the Storm Water Quality
Management Plan prepared for the project. The City will review and approve the Storm Water
Quality Management Plan prior to the issuance of grading and building permits to ensure that the
drainage system and BMPs comply with the Multiple Separate Storm Sewer System permit
requirements. As a result, the project's water quality impacts would be less than significant.