Long Beach Municipal Code Ch. 18.74 Low Impact Development Standards

The purpose of this chapter is to require the use of low impact development (LID) standards in the planning and construction of development projects. LID standards promote the goal of environmental sustainability by helping improve the quality of receiving waters, protecting the Los Angeles and San Gabriel River watersheds, maintaining natural drainage paths, and protecting potable water supplies within the City. The LID objective of controlling and maintaining flow rate is addressed through land development and stormwater management techniques that imitate the natural hydrology (or movement of water) found on the site. Using site design and best management practices that allow for storage and retention, infiltration, filtering, and flowrate adjustments achieve the goals of LID, advances sustainability and reduces the overall cost of stormwater management. The use of engineered systems, structural devices, and vegetated natural designs distributes stormwater and urban runoff across a development site maximizing the effectiveness of LID.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)

"Brownfield" means a piece of industrial or commercial property that is abandoned or underused and often environmentally contaminated, especially one considered as a potential site for redevelopment.

"Development" means any construction to build any new public or private residential projects (whether single-family, multi-unit or planned unit development); new industrial, commercial, retail and other non-residential projects, including public agency projects; new impervious surface area; or mass grading for future construction. It does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety.

"LID Best Management Practices Manual" means a manual of LID standards and practices for stormwater pollution mitigation, including technical feasibility and implementation parameters, alternative compliance for technical infeasibility, as well as other rules, requirements and procedures as the City deems necessary, for implementing the provisions of this section of the Long Beach Municipal Code.

"Multi-Phased Project" shall mean any Development or Redevelopment implemented over more than one phase and the Site of a Multi-Phased Project shall include any land and water area designed and being used to store, treat or manage stormwater runoff in connection with the Development or Redevelopment, including any tracts, lots, or parcels of real property, whether Developed or not, associated with, functionally connected to, or under common ownership or control with such Development or Redevelopment.

"Offsite Runoff Mitigation Fee" means fee paid to the City for the management of storm water runoff generated from three-quarter (0.75) inch water quality storm in excess of the storm water runoff that is infiltrated, evapotranspired and/or stored for use. The Offsite Runoff Mitigation Fee shall be used by the City to construct or apply towards the construction of an offsite mitigation project within the same sub-watershed that will achieve at least the same level of water quality protection as if all of the runoff was retained on site.

"Redevelopment" means land-disturbing activities that result in the replacement of more than fifty percent (50%) of an existing building, structure or impervious surface area on an already developed site. It does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety or grinding/overlaying and replacement of existing parking lots.

"Site" means the land or water area where any "facility or activity" is physically located or conducted, including adjacent land use in connection with the facility or activity.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)

A. The provisions of this section establish the requirements for LID compliance that shall apply to all new Development and Redevelopment projects in the City of Long Beach as noted in the following:

1. Residential Development of four (4) units or less:

a. For new Development less than one (1) acre, or if Redevelopment alters more than fifty percent (50%) of existing buildings, structures or impervious surfaces of an existing developed site, comply with the standards and requirements of this chapter and implement at least two (2) adequately sized LID BMP alternatives from the LID Best Management Practices Manual.

b. For new Development that is one (1) acre and greater, the entire Site shall comply with the standards and requirements of this chapter and the LID Best Management Practices Manual.

2. Residential Developments of five (5) units or more and nonresidential Developments:

For new Development, or if Redevelopment alters more than fifty percent (50%) of existing buildings, structures or impervious surfaces of an existing developed site, the entire Site shall comply with the standards and requirements of this chapter and of the LID Best Management Practices Manual.

3. Nonresidential Developments in the Port of Long Beach Harbor District:

For new Development or Redevelopment projects located in the Port of Long Beach Harbor District as designated in the Zoning Regulations, the site shall comply with the LID BMP alternatives set forth in the Port of Long Beach Post-Construction Design Guidance Manual and in the LID Best Management Practices Manual.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)

The following Development or Redevelopment projects are exempt from the requirements of this chapter:

1. Any Development or Redevelopment projects that creates, adds or replaces less than five hundred (500) square feet of impervious surface area;

2. Any Development or Redevelopment projects involving emergency construction activities required to immediately protect public health and safety;

3. Any Development or Redevelopment projects involving the grinding/overlaying, replacement, or restriping of existing permitted parking lots;

4. Any Development or Redevelopment projects where land disturbing activities result in the replacement of fifty percent (50%) or less of an existing building, structure or impervious surface area;

5. Any Development or Redevelopment projects that are technically infeasible pursuant to Subsection 18.74.040.B and comply with Subsection 18.74.050.B; or

6. Any Development or Redevelopment projects that do not require a building permit.

(ORD-25-0019 § 1(Exh. A), 2025)

A. Compliance with the LID standards of this chapter shall be demonstrated through a LID plan review. Permit applicant shall be required to submit a LID plan for review to the Building Official. The LID plan shall demonstrate how the project will meet the standards and requirements of this chapter and of the LID Best Management Practices Manual. A submitted LID plan shall indicate compliance with the following standards:

1. Stormwater runoff will be infiltrated, captured and reused, evapotranspired, and/or treated onsite through stormwater best management practices allowed in the LID Best Management Practices Manual.

2. The onsite stormwater management techniques must be properly sized, at a minimum, to infiltrate, evapotranspire, and/or store for use without any storm water runoff leaving the site to the maximum extent feasible, for at least the volume of water produced by a storm event that results from:

a. The volume of runoff produced from a three-quarter (0.75) inch storm event; or

b. The eighty-fifth (85 th ) percentile twenty-four (24) hour runoff event determined as the maximized capture stormwater volume for the area using a forty-eight (48) to seventy-two (72) hour draw down time, from the formula recommended in latest edition of the Urban Runoff Quality Management, WEF Manual of Practice No. 23/ASCE Manual of Practice No. 87; or

c. The volume of annual runoff based on unit basin storage water quality volume, to achieve eighty percent (80%) or more volume treatment by the method recommended in the latest edition of the California Stormwater Best Management Practices Handbook - Industrial/Commercial.

B. When the onsite LID requirements are technically infeasible, the infeasibility shall be demonstrated in the submitted LID plan and shall be reviewed in consultation with the Building Official. The technical infeasibility may result from conditions that may include, but are not limited to:

1. Locations where seasonal high groundwater is within ten (10) feet of surface grade;

2. Locations within one hundred (100) feet of a groundwater well used for drinking water;

3. Brownfield Development sites or other locations where pollutant mobilization is a documented concern;

4. Locations with potential geotechnical hazards; or

5. Locations with impermeable soil type as indicated in applicable soils and geotechnical reports.

C. If complete onsite compliance of any type is technically infeasible, a Development or Redevelopment project shall be required to comply with, at a minimum, all applicable requirements of Chapter 8.96 in order to maximize onsite compliance. An Offsite Runoff Mitigation Fee pursuant to Subsection 18.74.050.B shall be paid to the City of Long Beach's Stormwater Pollution Abatement Fund for the offsite mitigation of all remaining runoff that cannot feasibly be managed onsite. The funding will be applied towards the construction of an offsite mitigation project(s) within the same sub-watershed that will achieve at least the same level of water quality protection as if all the runoff was retained onsite.

D. A Multi-Phased Project must design a system acceptable to satisfy these standards and requirements for the entire Site during the first phase and will implement these standards and requirements for each phase of Development or Redevelopment projects of the Site during the first phase or prior to commencement of construction of a later phase, to the extent necessary to treat the stormwater from such later phase.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)

A. Permit applicants who seek to engage in new Development or Redevelopment as defined in this chapter by obtaining a building permit shall pay the required plan examination and permit fees as set forth in Chapter 18.06.

B. Permit applicants who seek to engage in new Development or Redevelopment that does not fully comply with the onsite requirements outlined in the LID Best Management Practices Manual and where technical infeasibility pursuant to Section 18.74.040.B is demonstrated, or as determined reasonably infeasible by the Building Official, may be permitted to pay an Offsite Runoff Mitigation Fee in lieu of compliance with this chapter. Payment of the fee shall be made prior to the issuance of a Certificate of Occupancy, Temporary Certificate of Occupancy, final inspection or construction approval for mobile home pad or pads, whichever occurs first, or at a time determined by the Building Official, in the manner and amount as set forth in the schedule of fees and charges established by City Council resolution.

C. A reduction in the Offsite Runoff Mitigation Fee will be permitted for Development and Redevelopment projects where partial onsite management of storm water runoff is provided based on the percentage of storm water that is managed on site through infiltration, evaporation, and/or capture and use as follows:

D. Any Development or Redevelopment projects that are exempted from this chapter shall have the option to voluntarily opt in and incorporate into the project the LID requirements of this chapter. In such case, the LID plan review, permit and Offsite Runoff Mitigation fees associated with the project shall be waived.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)

A. The Building Official shall prepare, maintain, and update, as deemed necessary and appropriate, the LID Best Management Practices Manual to include LID standards and practices and standards for stormwater pollution mitigation. The LID Best Management Practices Manual shall also include technical feasibility and implementation parameters, alternative compliance for technical infeasibility, as well as other rules, requirements and procedures as the City deems necessary, for implementing the provisions of this chapter.

B. The Building Official shall develop, as deemed necessary and appropriate, in cooperation with other City departments and stakeholders, informational bulletins, training manuals and educational materials to assist in the implementation of the LID requirements.

(ORD-25-0019 § 1(Exh. A), 2025; ORD-22-0033 § 1(Exh. A), 2022; ORD-19-0031 § 1(Exh. A), 2019; ORD-16-0026 § 1(Exh. A), 2016)