Low Impact Development - Regulatory Update Low Impact Development (LID) practices are being evaluated and developed at various governmental levels and localities. Much work is still required to reduce the failure rate of some practices (particularly in lower permeability soil types), develop standardized computational methods, develop data on maintenance costs and requirements, assess long-term effectiveness and measure how effective these practices are in terms of quality control, volume control, and peak flow rate (quantity) control. Non-structural LID practices, such as reduced pavement widths, "tighter" lot configurations and reduced building setbacks will require other ordinance changes. In the meantime, here is the latest on regulatory activities affecting LID implementation in the area: Virginia Low Impact Development Workgroup An ad hoc workgroup, comprised of representatives from local, state and federal agencies as well as engineering and environmental consultants and industry and environmental organizations, sent a letter to DCR, along with the framework of a DCR Technical Bulletin (which still needs design examples and computational methods), and a model ordinance (many localities would be better served by adjusting current ordinance in lieu of creating regulatory overlap) on February 9, 2004. Fairfax County Department of Public Works and Environmental Services (DPWES) DPWES has engaged a contractor to assist in developing LID practices to be incorporated in its Public Facilities Manual (PFM). It is working with a stakeholder's group to discuss the resulting 25 practices and case studies; from which six practices will be selected for inclusion in the PFM. Fact sheets on these practices and case studies are available at: http://www.lowimpactdevelopment.org/fairfax.htm. Corps of Engineers On December 17, 2004, the Norfolk District sent a response letter to those parties who submitted comments on its July 22, 2004 public notice. The notice proposed requiring the Corps LID site design checklist and runoff calculations worksheet be used in the project design process for prospective commercial and mixed-use developments that require a Corps permit and propose impacts to greater than ½ acre of nontidal wetlands or 300 linear feet of stream. The District also proposed to require that the completed worksheet be submitted with permit applications for the aforementioned developments so they know how LID was considered in the development of project plans. This information will be used to evaluate whether or not all appropriate and practicable measures to avoid and minimize impacts to waters and wetlands have been incorporated into project plans. The Corps' December 17, 2004 letter included a revised Site Design Checklist and LID Calculations Worksheet (also dated December, 2004), which incorporated an introduction that explains how the Corps would consider such practices and refined the design checklist and worksheet based on the public comments. In January, 2005, the Northern Virginia Building Industry Association (NVBIA) and the National Association of Industrial and Office Properties (NAIOP) responded with further comments on the revised checklist. Prince William County On March 2, 2005 the Prince William County Planning Commission held a workshop to learn more about LID. Several demonstration projects have been built, or are underway, in the County. Staff is evaluating and meeting with other localities to determine what changes in its Design and Construction Standards Manual (DCSM) are necessary to assure successful implementation on sites where LID is appropriate without requiring wholesale waivers of current requirements. Loudoun County The Loudoun County Facilities Standards Manual (FSM) changes proposed by the committee formed by the BOS recommended to the Planning Commission on February 28 (further discussion on March 14, 2005) that the language be changed to recommend, but not require, LID for drainage and SWM designs. Due to the unproven nature of the LID in many of the soil types found in Loudoun County there appears to be strong support to no longer require LID techniques at this time. For further information on local LID developments contact Bill Nell, P.E., Frank Graziano, P.E., or Mike Rolband, P.E., P.W.S., P.W.D.