LOW IMPACT DEVELOPMENT ( LID ) STANDARDS

Transcription

1 LOW IMPACT DEVELOPMENT ( LID ) STANDARDS January 9, 2013 Prepared By Truong Huynh, PE, CBO Superintendent of Building & Safety, Acting

2 OVERVIEW Part I LID Applicability and Requirements Part II Plan Check and Permit Process 2

3 PURPOSE Requiring the use of LID standards in the planning and construction of development projects will help to: Promote the goal of environmental sustainability by helping to improve the quality of receiving waters Protect the LA and San Gabriel River watersheds Maintain natural drainage paths Reduce the overall cost of storm water management Protect potable water supplies within the City 3

4 EFFECTIVE DATE February 19, 2013 LID standards shall not apply to those projects for which a building permit application has been filed for and deemed complete by the Department prior to this date. 4

5 PART I APPLICABILITY AND REQUIREMENTS 5

6 DEFINITION Development means any construction, rehabilitation, redevelopment or reconstruction of any public or private residential project (whether single-family, multi unit or planned unit development); industrial, commercial, retail and other non-residential projects, including public agency projects; or mass grading for future construction. 6

7 DEFINITION Redevelopment means land-disturbing activities that result in the creation, addition, or replacement of 500 sq. ft. or more of impervious surface area on an already developed site. Redevelopment includes, but is not limited to: the expansion of a building footprint; addition or replacement of a structure; replacement of impervious surface area that is not part of a routine maintenance activity; and land disturbing activities related to structural or impervious surfaces. 7

8 APPLICABILITY Apply to all new Development and Redevelopment projects: Residential Development of 4 Units Residential Developments of 5 Units and Nonresidential Developments 8

9 APPLICABILITY Residential Development of 4 Units For new Development < 1 acre, or if Redevelopment alters 50% of the impervious surfaces of an existing developed site, implement at least 2 adequately sized LID BMP alternatives (i.e., prescriptive BMPs Fact Sheet ) from the LID BMP Design Manual For new Development that is 1 acre, the entire Site shall comply with the LID BMP Design Manual 9

10 APPLICABILITY Residential Developments of 5 Units and Nonresidential Developments For new Development, or if Redevelopment alters 50% of the impervious surfaces of an existing developed site, the entire Site shall comply with the LID BMP Design Manual Where the Redevelopment alters < 50% of the impervious surfaces of an existing developed site, only such incremental Redevelopment shall comply with the LID BMP Design Manual 10

11 EXEMPTION Exempt any Development or Redevelopment projects that: Creates, adds or replaces < 500 sq. ft. of impervious area Involves emergency construction activities required to immediately protect public health and safety Interior building alteration or addition that does not expand the building footprint Does not require a building permit 11

12 REQUIREMENTS 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 BMP Design Manual. 12

13 REQUIREMENTS Compliance with the following standards: 2. The onsite stormwater management techniques must be properly sized, at a minimum, to infiltrate, evapotranspire, and/or store for use without any stormwater runoff leaving the site to the maximum extent feasible, for at least the volume of water produced by a storm event that results from: 13

14 REQUIREMENTS Compliance with the following standards: The volume of runoff produced from a 0.75 inch storm event; or The 85th percentile 24-hr runoff event determined as the maximized capture stormwater volume for the area using a 48 to 72-hr draw down time; or The volume of annual runoff based on unit basin storage water quality volume, to achieve 80% volume treatment. 14

15 TECHNICAL INFEASIBILITY Technical infeasibility may result from conditions that may include, but are not limited to: Locations where seasonal high groundwater is within 10 feet of surface grade Locations within 100 feet of a groundwater well used for drinking water Brownfield Development sites or other locations where pollutant mobilization is a documented concern 15

16 TECHNICAL INFEASIBILITY Technical infeasibility may result from conditions that may include, but are not limited to: Locations with potential geotechnical hazards Locations with impermeable soil type as indicated in applicable soils and geotechnical reports 16

17 OFFSITE RUNOFF MITIGATION FEE For runoff that cannot feasibly be managed onsite, one or a combination of the following shall be required: An Offsite Runoff Mitigation Fee shall be paid to the City of Long Beach s Stormwater Pollution Abatement Fund for offsite mitigation Offsite Runoff Mitigation Fee is $3.00 per sq. ft. of impervious area 17

18 OFFSITE RUNOFF MITIGATION FEE For runoff that cannot feasibly be managed onsite, one or a combination of the following shall be required: Reduction in the Offsite Runoff Mitigation Fee based on the % of stormwater runoff that is managed on site Stormwater Runoff Managed Onsite Fee Reduction Between 90% and 99% 75% Between 75% and 89% 50% Between 50% and 74% 25% 18

19 PART 2 PLAN CHECK AND PERMIT PROCESS 19

20 CITY AGENCIES The following city agencies or departments that may be involved with the review or permitting of the project: Development Services Building and Safety Bureau Development Services Planning Bureau Public Works Engineering Bureau Health s Environmental Health Bureau 20

21 Residential Development of 4 Units Plan Review Most projects will be reviewed over the public counter Planning and Building plan check Use Fact Sheet to choose 2 of the 6 prescriptive small scale residential LID BMPs to implement File covenant and agreement for BMP maintenance 21

22 Residential Development of 4 Units 6 Prescriptive Small Scale Residential LID BMPs Rain barrel Planter box Permeable pavement Rain garden Dry well Tree planting 22

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24 Residential Development of 4 Units Inspection Residential building inspection Submit completed and signed owner certification to inspector at time of final inspection 24

25 Residential Developments of 5 Units and Nonresidential Developments Plan Review Most projects will be submitted for regular plan check Planning, Building, Plumbing, and/or Public Works plan check Design to the standards in the LID BMP Design Manual File covenant and agreement for BMP maintenance 25

26 Residential Developments of 5 Units and Nonresidential Developments LID BMP Design Manual Determine appropriate BMPs (i.e., infiltration, capture and use, bio-filtration) BMPs shall be designed to manage and capture stormwater runoff Soils report to address site-specific conditions 26

27 Residential Developments of 5 Units and Nonresidential Developments Inspection Building, Plumbing, Public Works, Health inspections Submit LID Observation Report at significant stages of construction 27

28 SUMMARY Effective date is February 19, 2013 Applicable to all new Development and Redevelopment of 500 sq. ft. of impervious area Residential development of 4 units can use 2 of the 6 prescriptive LID BMPs Fact Sheet Residential development of 5 units and Nonresidential development must design to the standards in the LID BMP Design Manual 28

29 RESOURCE Visit Department s website at: Documents available on website: CLB LID BMP Design Manual 6 Prescriptive LID BMPs Fact Sheet Covenant and Agreement for Onsite LID Maintenance LID Observation Report LID Powerpoint Presentation 29

30 CONTACT Truong Huynh, PE, CBO Superintendent of Building and Safety, Acting Ph:

31 QUESTIONS THE END 31