By Martin Zoffmann
In order to become more resilient, the Miami-Dade County is looking for cost-effective approaches to manage stormwater to reduce flood risks.
One area in the county that has experienced more flooding historically is the Arch Creek Basin, a 2,838-acre drainage basin in an area with elevated groundwater. Therefore, the County arranged a challenge for ideas for creative proposals of all types on how to reduce flood risks in the Arch Creek Basin without significantly increasing energy demand for water management.
“The County was looking for small-scale interventions that can be used in neighborhoods, which will complement countywide, large-scale infrastructure projects. Ideally, these solutions would be passive and would require low or no continual energy inputs and they should be cost-effective so that they can be scaled up across the County,” says Steve Roy, Service Line Leader, Climate Adaptation and Green Infrastructure Service Line Manager, Ramboll US.
In collaboration with ACF ENVIRONMENTAL, a custom design and manufacturing facility creating technology for the construction and stormwater industries, Ramboll’s Liveable Cities Lab, based in Boston, decided to take up the challenge – and the design proposal was selected as one of the winners.
“Our proposed solution is to bring Blue-Green Infrastructure to the Arch Creek Basin by combining the Focal-Point technology removing pollutants from urban stormwater runoff with Ramboll’s cloudburst stormwater design approach,” Steve Roy explains.
The added component of the Blue-Green Infrastructure (BGI) approach is to use the streets as stormwater conveyance and direct this water to detention green space. BGI is sustainable and results in multiple co-benefits for residents including more green space and improved recreation.
BGI is effective in improving water quality during every day rain events and in contributing to a controlled flooding of carefully selected detention areas during more extreme rain events, potentially caused by cloudbursts or hurricanes. This approach is consistent and can accommodate a future city slough park concept that will be developed as the longer-term solution to flooding in this area.
In their acceptance, the challenge organizers stressed the Blue-Green Infrastructure element in the proposal as well as the focus on cost-efficiency:
“We were particularly impressed with the proposal’s emphasis on innovative ways to manage stormwater with blue-green infrastructure. Similarly, we appreciate the emphasis on cost-effectiveness as this is an essential component of any approach,” says Jim Murley, Chief Resilience Officer, Regulatory and Economic Resources Department in Miami-Dade County.
The design competition was supported by the efforts of City Mart to help organize and publicize this competition for Miami-Dade County.
Miami-Dade County is now looking into possibilities for funding and implementing measures potentially based on the proposal from Ramboll and ACF ENVIRONMENTAL.