Item A: Low Impact Development: Results of Review

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Stormwater Development and Design Standards (Stormwater Management Manual) – Medium Potential There is potential to further enhance LID practices by modification of the current land use regulatory framework by incorporating in the development standards and the SMM a required hierarchy of stormwater management practices and facility types to implement LID practices whenever feasible prior to use of stormwater structural facilities. The stormwater standards in the Land Use Code require that stormwater management facilities be selected from and designed utilizing the City’s adopted Stormwater Management Manual (SMM). The SMM provides the administrative tool by which staff, developers, and design professionals implement and comply with the city’s stormwater development standards. Currently, the development standards and manual allow selection of facility types that are both consistent with LID practices and facility types which do not incorporate LID objectives (structural facilities). As such it is an applicant’s option whether or not to implement LID-compatible stormwater management facilities. While this allows flexibility in methods for meeting stormwater management objectives at the site level, it does not maximize use of LID practices for stormwater management. Additional Stormwater Standards – Low Potential Tentative PUDs are required to demonstrate how stormwater runoff from the site will not create significant negative impacts on natural drainage courses either on-site or downstream including, but not limited to, erosion/scouring. PUDs generally achieve greater degree of LID objectives than development outside of the PUD process. Opportunities may exist to more specifically expand the use of LID practices within the PUD process through focused requirements and/or considering additional incentives. Impervious Surface Area (ISA) Limits Reducing the amount of impervious area created with new development is a direct LID practice. Forms of ISA limits addressed within the land use code are summarized below. Note that parking and landscaping requirements also affect the magnitude of ISA and are discussed separately. Impervious area reduction is a desirable LID element to pursue given its potential to meet multiple LID objectives, e.g. reduction and infiltration of runoff. Medium Potential: Expand definition of Lot Coverage to include impervious surface areas in addition to buildings. Barriers: complexities of implementing changes to regulations and existing standards; challenges to balancing and integrating LID objectives with other City initiatives and priorities (could affect lot size/density objectives); potential to decrease available site areas for desired uses. Elements of impervious surface area limitations were reviewed in further detail as follows. Lot Coverage – Medium Potential This is defined by Eugene Code (EC) to be the portion of a lot which, when viewed directly from above would be covered by a building or structure or any part thereof (with some exception, see glossary). R-1 Low Density Residential and R-2 Medium Density Residential zones allow up to 50% lot coverage while Row Houses in any residential zone allow up to 75% coverage. Nonresidential development has no regulated minimum/maximum ISA; however, many zones do require that a percentage of the development site be landscaped. Currently EC only regulates the lot coverage of structures. The primary opportunities would be to include additional zones and other types of ISA coverage; e.g. concrete driveways and walkways, in calculation of total lot coverage allowed. Use of pervious pavements could be indirectly encouraged. To preserve density objectives and standards, the percentages of lot coverage allowed would need to be reviewed to consider the modified bases for measurement. Floor Area Ratio (FAR) Calculation – Low Potential The FAR calculation applies to Downtown (within the /TD Transit Oriented Development Overlay Zone) and nodal development areas (within the /ND Nodal Development Overlay Zone). Current code establishes a minimum FAR, calculated as area of floors in buildings divided by land area of development September, 2008 City of Eugene LID Report, Page 6 of 26