HomeMy WebLinkAboutSDP2021-0020; LEGOLAND PROJECT 2023; EQUIVALENT AREA CALCULATIONS AFTER THE INCLUSION OF LEGOLAND PROJECT 2023; 2021-11-24Equivalent Area Calculation after the inclusion of LEGOLAND LLC-2023 for
Water Quality and Hydromofication Purposes
Date: 11/24/2021
Summary
The purpose of this letter is to provide calculations updating the remaining Equivalent Area after the incorporation
of the LEGOLAND LLC-2023 project as part of the LEGOLAND future developments that are using the LEGOLAND
regional BMPs for Water Quality and Hydromodification Compliance. Projects using LEGOLAND regional BMPs do
not need to design BMPs for Water Quality or Hydromodification compliance as long as they demonstrate that
their impact area is included as part of the area treated by the regional facilities.
According to the LEGOLAND Regional Water Quality and Hydromodification BMP report (SDP 15-26 / CDP 15-50,
dated 6/30/18) the regional LEGOLAND Water Quality and Hydromodification facilities can treat up to 45.766 acres
of additional equivalent area for Water Quality purposes and up to 72.771 acres of additional equivalent area for
Hydromodification purposes. After the letter dated 11/6/2018 associated with LEGOLAND 2020, these areas
reduced to 44.630 acres and 71.635 acres respectively. To REC and CDR knowledge, no other project have
occurred and those values after LEGOLAND 2020 are considered the remaining values for LLC-2023 calculations.
The project included in this calculation (LEGOLAND LLC-2023) will use 0.348 acres of equivalent area (see
calculations in page 2) Therefore the remaining equivalent area for Water Quality will reduce to 44.282 acres and
the remaining equivalent area for Hydromodification will reduce to 71.287 acres after LEGOLAND LLC-2023.
It must be emphasized that any project after LEGOLAND LLC-2023 must use the remaining amounts highlighted in
this letter. The City of Carlsbad and/or the person designated by it must keep track of the remaining equivalent
area so that: (a) a proper accountability in time of the remaining equivalent area capacity left after each project is
kept so that future LEGOLAND projects are informed, and (b) once the equivalent area amount is either exhausted
or no longer usable for any reason future LEGOLAND projects are notified to prepare proper treatment BMPs.
Prepared by:
Luis ra,P,cPSWQ,ToR, D.WRE.
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S S
WATER QUALITY AND HYDROMODIFICATION EQUIVALENT AREA CALCULATION
Project Name: LEGOLAND LLC 2023
(Assigned # for Regional LEGOLAND BMP accountability): 1
Date of Calculation: 11/24/2021
Total Area Impacted: 0.526 acres
Existing pervious 0.243 acres
Existing impervious: 0.283 acres
Existing self-contained: 0.000 acres
Proposed pervious: 0.157 acres
Proposed impervious: 0.369 acres
Proposed self-contained: 0.000 acres
C coefficient (Post-dev.): 0.661
Existing area = proposed area? r YES
Equivalent Area: 0.348 acres
Not Including this project, this is the status of treatment for LEGOLAND:
Water Quality Equivalent Area: 44.630 acres
Hydromodification Eq. Area: 71.635, acres
.....
After this project, this will be the remaining treatment for LEGOLAND
Water Quality Equivalent Area 44.282 acres
Hydromodification Eq. Area 71-287 acres
Notes:
Values in blue italics must be provided. Values in bold are calculated.
(15) and (16) are remaining values after the project and must be used for
projects calculated after the date included in this table.
C. To REC and CDR knowledge, there have been no other LEGOLAND Projects from the date
of the last calculation (LEGOLAND 2020, 11/6/2018) and this estimate (LLc-2023).
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