Millions of dollars are spent annually by municipalities implementing green and grey stormwater control measures (SCMs) to meet objectives such as flood control or water quality permit compliance. More recently, municipalities are also considering additional benefits to the environment and local communities that could be generated by SCMs. With so much capital at stake, accurate estimation of the performance and life cycle costs (LCC) of the potential SCM alternatives is important. This work gives an overview on an integrated decision support tool (i-DST) which evaluates the benefits and tradeoffs of green, grey, and hybrid SCMs. The i-DST watershed scale tool utilizes the EPA’s System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) to optimize the types and numbers of SCMs in order to minimize cost and maximize a user selected evaluation target. Prior work has shown that 1) the optimal stormwater management plan is unique for each watershed, 2) greyer SCMs offer benefits that should be considered, and 3) LCC and co-benefits may be the tipping point in choosing one SCM over another. Initial testing of the i-DST planning tool is being undertaken on three watersheds across the United States (Los Angeles, CA; Denver, CO; Charlotte, NC). The fully developed iDST tool includes a BMP pollutant decay rate calibration tool, improved list of evaluation targets, greyer underground detention/infiltration SCMs, a LCC estimation, and a community co-benefit quantification. Modeling results demonstrate how the tool takes into account the unique physical/hydrologic characteristics and the municipal needs of the watershed in order to assist stakeholders in making holistic decisions for the optimal stormwater management plan.

Using a new integrated decision support tool (i-DST) to optimize the benefits and tradeoffs of greener to greyer stormwater infrastructure in three cities across the United States.

The International Low Impact Development Conference highlights interdisciplinary practice, research, and implementation of Low Impact Development (LID), Green Infrastructure (GI), Sustainable Urban Drainage Systems (SUDS) and Water Sensitive Urban Designs (WSUD). The focus of this conference was on using our past and present understanding of LID to tune management programs, design practice, and operation and maintenance into the future.



NOTE: Due to the COVID-19 pandemic, this conference was held virtually. The proceedings have been published to provide readers access to the information that was presented.

[Paper Proceedings](https://doi.org/10.1061/9780784483114)

Conference DOI: https://doi.org/10.26226/m.6317827c362f600015b4eb73