The Assessment of Water Quality conducted by Dr. Solo-Gabriele outlined that rainfall is the main predictor of poor water quality within the canal. The unique characteristics of the waterway limit flushing as a shallow and narrow canal. The primary source of bacteria was identified as waste deposited on surfaces that drain toward the canal from the 81-acre catchment area to the east. The existing stormwater system in this area is gravity-based and rainwater picks-up pollutants on land, enters catch basins, and exits outfalls untreated. North Beach is densely populated, and the University of Miami team identified many sources contributing to degraded water quality including exotic and feral animal feces, the homeless population, dog waste, litter, and leaking dumpsters in commercial areas. In addition, the aging sanitary sewer system cannot be discounted as it is in need of upgrades and is located near the stormwater conveyance system. Even though testing led by the Public Works Department has not indicated significant deficiencies such as a major break, there is possibility of leakage not identified through the infrastructure testing due the age of the system and private connections.
In addition to the infrastructure testing performed, staff from several Departments have worked to address many of the above ground findings. Sanitation performs weekly street sweeping and twice daily garbage can collection on Park View Island, Code Compliance performs daily sweeps of the area, and Homeless Outreach and Community Services performs dedicated outreach to homeless individuals.
In light of the Assessment of Water Quality report, staff has developed an action plan that combines the study recommendations with actions that include both funded and unfunded items (Attachment B). A summary of infrastructure-based items likely to have the most significant impact are highlighted below.
· Line aging wastewater pipes to prevent exfiltration (in progress), replace air release valves in North Beach (in progress), and work with DERM to install manhole smart covers to detect rising levels before overflows occur. Lining is currently funded for Park View Island for $338,227. Additional lining will be needed outside of the North Shore D/ Town Center project. Sampling efforts are underway to evaluate potential positive impact to the canal.
· Identify additional way to address litter and waste in the waterway and vicinity.
· Install manhole smart covers to detect rising levels before overflows occur. This effort is being funded by Miami-Dade County as part of a countywide effort.
· Retrofit existing gravity stormwater system with water quality treatment devices within the vicinity of the canal such as bar racks to prevent litter from entering the waterway. The estimated cost for this is $2.2 million, with $200K in FY24 and $2M in FY25.
· Dredge the waterway to improve flushing and remove contaminated sediment with the canal. The Environment & Sustainability Department currently has $500K in funding to complete initial surveys required for dredging (bathymetric and geotechnical), but funding would need to be identified to complete design, permitting, and completion of a dredging project. Dredging of the canal is estimated to cost $2M in FY24/25.
· The North Beach Town Center Improvements will include new design and replacement of the stormwater and sanitary sewer infrastructure in the catchment area; this would include outfall relocations and water quality treatment pump stations. The City was awarded $10 million in Resilient Florida funding towards the design. The project is called North Shore D/ Town Center with This is estimated at $137M, with $19.5M in FY25 and $104M in FY27.
In addition, Public Works and Environment & Sustainability staff have sought grant funding for enhanced hybrid living shorelines to complement North Beach Town Center improvements and will continue to seek funding for initiatives that align with the goals of improving water quality and the quality of life for residents.