Monitoring Sites:

  • Holden Arboretum Visitor Center
  • Old Woman Creek Reserve Visitor Center
  • Orange Village Service Facility
  • Perkins Township Administrative Offices
  • Ursuline College
  • Willoughby Hills Community Center

Project Team:

Project Products:

NERRS Science Collaborative 

Innovative Stormwater Management in Northern Ohio

The “Implementing Credits and Incentives for Innovative Stormwater Management” project promoted the implementation of low impact development (LID) stormwater control measures (SCMs) that reduce the impacts of stormwater runoff on Ohio’s coastal communities and Lake Erie and worked to improve state and local stormwater policies.  A project team led by the Chagrin River Watershed Partners (CRWP) and Old Woman Creek National Estuarine Research Reserve (OWC NERR) assessed the performance of bioretention and permeable pavement on poorly draining soils by collecting and analyzing hydrologic data from 3 bioretention cells, 4 permeable pavement applications, and a permeable pavement-cistern treatment train to determine runoff reduction by these SCMs. This case study document includes brief descriptions of each site and monitoring results.  The National Estuarine Research Reserve System (NERRS) Science Collaborative funded this project.

 

The bioretention cells we monitored reduced outflow by 36-60% through exfiltration and evapotranspiration.  The monitored permeable pavement applications reduced outflow by 17 -98%.  The permeable pavement application with the smallest reduction in outflow drained an impervious area much larger than what is recommended by Ohio’s stormwater manual.  The permeable pavement application with the greatest reduction in outflow had no run-on from impervious surfaces, areas of well-draining fill within the subgrade soil beneath the permeable pavement, and a subdrain beneath the permeable pavement designed to dewater the groundwater table.  Please see the monitoring report for more detail on the hydrologic benefits of bioretention and permeable pavements on poorly draining soils.

 

SWMM and DRAINMOD modeling allowed for further assessment of the impact of design choices on SCM performance. The DRAINMOD modeling report includes results of sensitivity analyses and projections of future climate performance completed using calibrated models of bioretention and permeable pavement. The SWMM technical memorandum details results of sensitivity analyses for 9 SCMs with uncalibrated models.

 

This project resulted in updates to the bioretention design specification in Ohio’s stormwater manual, Rainwater and Land Development, and laid the technical foundation for a runoff reduction crediting mechanism to be added to Rainwater and Land Development. The runoff reduction guidance will provide a pathway for meeting the state’s NPDES water quality volume (WQv) requirement through runoff reduction, as well as a mechanism for crediting the runoff reduction benefits of LID SCMs toward meeting local peak discharge requirements. This project also informed updates to CRWP’s model stormwater management code.

 

Additionally, project team members provided technical assistance and training to many engineers and local government staff members over the course of the project to increase their capacity to implement LID. Presentations from training on June 9 and 10, 2015 are available here. NCSU’s rainwater harvesting tool incorporated Ohio data through this project.

 

A Collaborative Learning Group (CLG) of local and state stormwater regulators and consulting engineers provided iterative guidance and feedback to the project team. Project grant reports are available here.

 

This material is based upon work supported by the University of New Hampshire under Award No. Cooperative Agreement No. NA09NOS4190153 (CFDA No. 11.419) from National Oceanic and Atmospheric Association. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the University of New Hampshire or the National Oceanic and Atmospheric Association.