Скачать или смотреть MuniCon 2019 | 2.9 | Assessment Protocol for Rain Garden/Bioretention Facility Effectiveness

Presented at the 2019 Washington State Municipal Stormwater Conference (April 25, 2019)

Presenters: Robert Simmons (Washington State University)


Abstract.

Rain gardens and bioretention facilities are considered to be effective tools in the Low Impact Development (LID) toolbox and are being implemented at an accelerating rate. Project partners, WSU Extension, Stewardship Partners and the City of Puyallup have developed a rain garden and bioretention assessment protocol that builds our region’s capacity to monitor basic functions of rain gardens and bioretention facilities and assess factors influencing their success and failure at a regional scale. The protocol was developed to allow ease of implementation, repeatability across large geographic scales and multiple implementers, and provide data of scientific and adaptive management value. The key questions that this project answers are:

What attributes of rain garden/bioretention functionality measured by volunteers and staff through visual observations and simple field or lab tests correlate best predict functional success of the system?
What design, construction, and maintenance actions identifiable by volunteers and staff have the greatest correlation with functional success of a rain garden/bioretention facility?

Through an extensive literature search and two rounds of pilot studies in 4 Puget Sound counties, our team of academics, permittees, and on-the-ground experts with extensive experience in measuring rain garden/bioretention function have developed effectiveness metrics as a framework for the evaluation of rain garden/bioretention effectiveness. This framework also provides insight into how installation methods and maintenance practices predict functional success of bioretention/rain garden success. The targeted effectiveness metrics include soil characteristics, infiltration capacity, bypass/overflow frequency, plant viability, public acceptance, maintenance issues, and whether or not the installation is still collecting runoff.

This presentation will provide an overview of the metrics, data methodology, challenges and successes, how jurisdictions can access and adapt the protocol for their use, protocol limitations, and an overview of the results using the protocol on 41 sites in the Puget Sound region.

This replicable, streamlined monitoring protocol will enable NPDES permittees to monitor progress consistently, economically and effectively. It will also be a useful tool to compare and share data between municipalities allowing for region-wide evaluation of progress as well as foster collaborative approaches to shared obstacles.
Learning Objectives.

This presentation will provide an overview of a useful tool that enables permittees to assess the functional success of rain garden and bioretention facilities. The participants will learn how to access the protocol, protocol limitations, and long term utility of the data for asset management, facility design, and investment. It will enable permittees to validate the effectiveness of installed facilities.