Go Big: The Case for Regional Treatment in Santa Clara County
Title of Presentation: GO BIG: THE CASE FOR REGIONAL TREATMENT FACILITIES IN SANTA CLARA COUNTY
Purpose of the Talk
The intent of this presentation is to demonstrate, using a current project example, how open space resources contained within the Santa Clara Valley’s stream corridors can be used effectively to address the need for regional stormwater management facilities.
Compliance with MS4 permit requirements that mandate the use of Low Impact Development treatment on new and redevelopment projects has proved to be a challenge for builders of high density and transit-oriented development projects in the Santa Clara Valley. The emphasis on more compact development dictated by local and regional land use plans, coupled with constraints on the use of infiltration-based measures or capture and re-use systems, including high clay content of the native soils, on-site utility conflicts, and overall lack of available space for landscape-based controls have focused project developers’ attention on potential alternatives to on-site treatment facilities. The “Alternative or In-Lieu Compliance” provision of the local MS4 permit allows a project applicant to provide a portion of the project’s required LID treatment at an off-site facility, or Regional Project, located within the same watershed as the proposed project. The problem is that currently there are no such regional facilities in existence anywhere in the Santa Clara Valley. The presentation will describe the Berryessa Crossing project, a major urban village development in San Jose featuring a regional stormwater treatment solution that serves as a model for future regional facilities that could be constructed in similar locations throughout the area to address the challenge.
Summary of the Tools, Ideas and Concepts
The learning objectives for this presentation include the following:
• explore alternative compliance options to on-site conformance with LID requirements in new development projects;
• learn how to achieve multiple policy objectives while developing engineered solutions to stormwater management on a large scale;
• develop strategies for utilizing existing resources to resolve design challenges posed by current stormwater treatment regulations.
The presentation is intended to be thought-provoking, and questions from the audience will be encouraged. Slides used in the presentation will incorporate terms, illustrations and photographs that are easily understood by the target audience – civil engineers, land use planners and stormwater professionals, and should facilitate participation by all members of the audience.
Addressing the Conference Theme
This year’s theme, “Stormwater—Are We Making a Difference?” questions the link between stormwater programs and environmental outcomes and reflects the spatial and temporal complexity of stormwater improvement in urban areas and the need for innovative approaches.
The urban stormwater management approach featured in this presentation is innovative because it re-thinks the standard stormwater management approach encouraged by permitting agencies - that of attempting to combine site design techniques and civil engineering methods to convey runoff to LID facilities on individual, overly-constrained sites. It provides an alternative solution that minimizes potential conflicts between: a) density requirements and available onsite landscape areas; b) private property and public street maintenance responsibilities; and c) the mixing of treated and untreated runoff in public conveyance systems. It takes advantage of a unique locally-available resource, riparian setback areas, to provide a simplified treatment system that is more efficient, and effective for pollutant removal and volume reduction.