Solutions for Biscayne Bay: Stormwater
After rain events, stormwater flows along roads and sidewalks, picking up contaminants like oil, debris, fertilizers, pet waste, and pesticides. These pollutants are then carried into the Bay through a network of storm drains, outfalls, culverts, and groundwater. Before rapid urbanization, South Florida's natural ecosystems retained and slowly released rainwater gradually into the Bay, allowing nutrients to attenuate along the way naturally. Now, stormwater systems are designed to move water quickly.
Miami-Dade's stormwater infrastructure faces growing challenges due to sea-level rise and shifting precipitation patterns. Some components of this infrastructure have already stopped functioning correctly, and water from the Bay – previously lower than the base of the stormwater management system – has begun moving back up the system and flooding the streets. This issue, known as "sunny day flooding," not only increases the number of flood events that inconveniencing flood events our day-to-day lives but also increases water pollution. Just 6 inches of increase in mean high tide level has resulted in over 400% more flooding events.
Municipalities in Miami-Dade County are required to obtain permits to maintain stormwater sewers, as well as inspect and investigate pollution control structures and cases of illicit pollution. Similarly, industrial facilities are obligated to have permits for their operations when their runoff poses a risk of introducing pollution into the stormwater system. We have documented a high level of non-compliance by both municipalities and industrial facilities in Miami-Dade County.
Green Stormwater Infrastructure (GSI) is a type of nature-based solution that manages stormwater close to where it falls. In addition to reducing flooding, GSI improves water quality, increases local water supply (though not usually for drinking but for other purposes such as landscape irrigation and toilet flushing), mitigates heat by decreasing air temperature through evapotranspiration, and captures air pollution that leads to smog. Other positive effects include health benefits, as decreased air pollution and temperatures along with improved water quality results in the reduction in heat-related illnesses. Instead of relying on traditional hardscapes that are unsustainable – and that are killing the Bay – we need to leverage the power of green infrastructure to build community resilience. Historically marginalized communities are disproportionately impacted by climate change, underscoring the need for targeted design and implementation of Green Stormwater Infrastructure (GSI) in these regions. Given this, it is important to approach GSI with a planning, design and outreach process that prioritizes the advancement of equity. One valuable resource to facilitate this is the Equity Guide for Green Stormwater Infrastructure Practitioners, developed by the Green Infrastructure Leadership Exchange.
- Integrated Stormwater Management: Develop an integrated stormwater management plan that takes into account sea level rise projections and rising water levels, ensuring the system’s resilience to climate change.
- Green Stormwater Infrastructure Implementation: Promote the integration of green stormwater infrastructure into urban planning to enhance water retention, slow down stormwater runoff, and reduce the impact of flooding and pollutant loads while also encouraging habitat and wildlife.
- MS4 Permit Compliance: Work to improve compliance with MS4 (Municipal Separate Storm and Sewer Systems) permits, emphasizing the responsible discharge of stormwater and the reduction of pollutant loads into local water bodies.
- Industrial Permit Compliance: Enhance industrial permit compliance by local industries to reduce pollution in stormwater runoff, safeguarding water quality and public health.
- Storage Capacity Expansion: Increase the storage capacity within the stormwater system by preserving open spaces for stormwater retention, reducing the risk of flooding and improving water quality.
- Advanced Treatment Levels: Improve the treatment levels within the stormwater system to significantly reduce pollutant loads, further enhancing water quality and ecological health.
- Develop a Green Infrastructure Master Plan: Create a comprehensive green infrastructure master plan to aid in securing state and federal grant funding for sustainable stormwater projects.
Regulatory and Compliance Enhancements:
- Review existing local codes and enact changes to promote resiliency and green infrastructure in stormwater management practices. Existing code that was written over a decade ago can be hostile to innovative low impact designs and green infrastructure.
- Increase stormwater permit enforcement and compliance for the municipality and industrial properties within it.
- Conduct regular inspections for illicit discharges and implement a specific timeframe for such inspections
- Inspect and clean pollution control structures more frequently (dependent on a Stormwater Asset Management system)
- Implement Pilot Stormwater Projects: Initiate pilot projects to test and demonstrate the effectiveness of green stormwater solutions in the local context. Leverage grants from the EPA and DEP that support stormwater management and infrastructure improvements.
Stormwater Infrastructure Improvement:
- Install stormwater grates at outfalls to prevent debris from entering water bodies and causing pollution.
- Incorporate filtration systems to capture and remove pollutants.
- Create a process to clean any debris and pollution captured.
- Implement a real-time Stormwater Asset Management system for infrastructure performance feedback.
- Review and digitize municipal stormwater maps to modernize data management.
- Evaluate the use of stormwater pumps and consider alternative methods to moving water.
- Increase street sweeping frequency to improve debris and pollutant removal. Frequency should be dependent on a Stormwater Asset Management system.
- Community Outreach and Education: Inform the community on the impacts of stormwater pollution and the measures they can take to reduce contamination. Place “no dumping” signage at all storm drains to raise public awareness and discourage illicit discharges.
- Stormwater Outfall Testing and Management: Increase the frequency of inspections for stormwater outfalls to ensure proper functionality. Conduct a bi-annual sampling of all stormwater outfalls during or just after rain events. Test for nutrients, bacteria, etc. to quantify pollution entering the watershed.
- NOAA Coastal Habitat Restoration and Resilience Grants for Tribes and Underserved Communities, Under the BIL and IRA: this includes $45 million under the Bipartisan Infrastructure Law and Inflation Reduction Act for projects that will advance the coastal restoration and climate resilience priorities of tribes and underserved communities.
- Florida DEP Resilient Florida grants: The Resilient Florida Program includes a selection of grants that are available to counties, municipalities, water management districts, flood control districts and regional resilience entities. To effectively address the impacts of flooding and sea level rise that the state faces, eligible applicants may receive funding assistance to analyze and plan for vulnerabilities, as well as implement projects for adaptation and mitigation.
- National Fish and Wildlife Foundation: National Coastal Resilience Fund: The National Coastal Resilience Fund restores, increases and strengthens natural infrastructure to protect coastal communities while also enhancing habitats for fish and wildlife. Established in 2018, the National Coastal Resilience Fund invests in conservation projects that restore or expand natural features such as coastal marshes and wetlands, dune and beach systems, oyster and coral reefs, forests, coastal rivers and floodplains, and barrier islands that minimize the impacts of storms and other naturally occurring events on nearby communities.
- EPA Clean Water State Revolving Fund: Funding Resilient Infrastructure and Communities: In addition to funding infrastructure projects, there is specific funding for stormwater assistance for any public, private, or nonprofit entity for measures to manage, reduce, treat, or recapture stormwater or subsurface drainage water.
- EPA urban runoff for illicit discharges model ordinances: The model ordinances in this section include language to address illicit discharges in general, as well as illicit connections from industrial sites. The language is borrowed from a number of ordinances and communities will need to assess what enforcement methods are appropriate for their area.
- EPA model ordinances for stormwater control: This section includes model ordinance language, which focuses primarily on the maintenance of stormwater BMPs, and includes the elements of design, routine maintenance, and inspections.