'1 ;i II CITY OF WOODINVILLE, WA REPORT TO THE CITY COUNCIL 17301 133rd Avenue NE, Woodinville, WA 98072 WWW.CI.WOODINVILLE.WA.US To: By: Honorable City Council Thomas E. Hansen, P.E., Public Works Director Date: Subject: Discussion of the Implementation of Low Impact Development Guidelines and Princi les FINANCIAL ACTION SUMMARY Ex enditure Re uired July 19, 2016 $0 ISSUE: Shall the City Council receive a report concerning the implementation of Low Impact Development (LID) Guidelines and Principles into City Code requirements? STAFF RECOMMENDATION: To receive the report. BACKGROUND/ANALYSIS: The City operates it's stormwater drainage system under the requirements of National Pollution Discharge Elimination System (NPDES) Phase II Permit issued by the Washington State Department of Ecology for the years 2013-2018. One of the permit requirements in Section S5.C.4.f, requires the following of permittees, including the City of Woodinville, that "No later than December 31, 2016, permittees shall review, revise and make effective their local development, related codes, rules, standards or other enforceable documents to incorporate and require LID principals and LID Best Management Practices (BMPs)." LID principals are the means and methods to handle stormwater runoff from developed properties in a way that would mimic mother nature if the site was not developed and left in its original undeveloped state. In late 2015, City staff and our On-Call Civil Engineering Consultant, Otak, Inc., started working on this requirement, identifying potentially necessary Woodinville Municipal Code (WMC) and Transportation Infrastructure Standard revisions. Collectively we have identified over 40 potential revisions that should be considered. Staff is currently preparing drafts of the proposed revisions for future consideration by the City Council, and later consideration and hopeful adoption by the City Council. Staff will be presenting information to the City Council at the meeting on the regulatory environment, further information on what LID is, and the areas in the Code and Standards that staff believes should be changed to meet this permit requirement. ALTERNATIVES: 1. Receive the report and provide direction to staff. 2. Request additional information. RECOMMENDED ACTION: INFORMATION ONLY. 1 11
Implementation of Low Impact Development (LID) Guidelines and Principals into City Code Requirements Presentation to the City Council July 19, 2016
BACKGROUND City operates it s stormwater drainage system under a National Pollutant Discharge Elimination System (NPDES) Permit issued by the Washington State Department of Ecology. Current permit effective 08/01/13 to 07/31/18. Section S5.C.4.f of the current Permit No later than December 31, 2016, Permittees shall review, revise and make effective their local development-related codes, rules, standards, or other enforceable documents to incorporate and require LID principles and LID BMPs. The intent of the revisions shall be to make LID the preferred and commonly-used approach to site development. The revisions shall be designed to minimize impervious surfaces, native vegetation loss, and stormwater runoff in all types of development situations. Permittees shall conduct a similar review and revision process, and consider the range of issues, outlined in the following document: Integrating LID into Local Codes: A Guidebook for Local Governments (Puget Sound Partnership, 2012).
WHAT IS LOW IMPACT DEVELOPMENT (LID)? From the Department of Ecology NPDES Permit for Phase 1 Permittees LID Definition: Low-impact development (LID) is a stormwater and land use management strategy that strives to mimic pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation, and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design. Tom Hansen s Translation for us normal folk: So stormwater/rainfall drains like it did before Western Civilization got here in 1850 and screwed it up!
THE GOAL of LID Emulates Historic (pre-1850) Runoff Patterns
Examples of LID Techniques that can be Incorporated into Code Permeable Pavers
Examples continued... Permeable Pavement
Examples continued... Street Design Concepts Typical Today Using LID Techniques
Examples continued... Street Design Concepts Typical Today Using LID Techniques
Examples continued... Landscaping Concepts Typical Today Using LID Techniques Using Bio-retention Swale/Raingarden
PRELIMINARY ANALYSIS OF CITY CODES AND STANDARDS THAT SHOULD BE REVISED TO INCORPORATE LID Transportation Infrastructure Standards - Changes Low-Density Residential Streets Slope in one direction Bio retention / infiltration on edge instead of pipes and catch basins Reduce section width Allow permeable sidewalk in limited situations. Allow bio-retention swales / infiltration swale along all types of streets and in planter strips. Reduce pavement area of cul-de-sacs Promote Hammerheads. Allow Permeable Pavement in parking lots and private roads. Utilities to be place under develop roadway on right-of-way, not on shoulder or outside of pavement.
INCORPORATE LID UPCOMING CODE CHANGES Modify and Adopt Grading Code Adopt 2016 King County SWM Manual Require LID to be the first choice on how to handle stormwater on development and re-development projects. Modify landscape code to allow bio-retention / infiltration facilities within required landscape area. Restrict Parking - Establish both minimum and maximum number of stalls required / allowed. Limit amount of impervious surface in R Zones and reduce credit for pervious hardscape areas. Allow narrower driveways and strip driveways. Address long term maintenance of bio-retention and infiltration facilities. Post construction soil tilling. Require a minimum amount of landscaping.
PROPOSED SCHEDULE July Aug 2016 Sept Oct 2016 Sept Oct 2016 Oct Dec 2016 Staff prepare Draft revisions to Codes and Standards Public Open House Planning Commission - Study Sessions, Public Hearings, Recommendation City Council Study Sessions, Public Hearings, Adoption
QUESTIONS?