How Dubuque Turned Recycled Bottles Into Floating Islands to Revive Bee Branch Creek
In an effort to manage chronic flooding, the city of Dubuque, Iowa, installed 14 floating islands built from thousands of recycled water bottles, transforming a restored creek into a thriving urban ecosystem.
Cities facing chronic flood risks often turn to heavy engineering solutions like concrete channels, larger pipes, and higher walls. However, in Dubuque, Iowa, urban planners pursued a different approach by reopening an old creek and deploying an unusual ecological experiment involving thousands of recycled plastic bottles.
According to an online report by IECA News, the city installed 14 floating islands in Bee Branch Creek in 2017. Constructed using the plastic equivalent of about 67,000 BPA-free water bottles, the system spans a total of 2,674 square feet. The initiative was designed to serve multiple functions beyond simple aesthetics, helping to protect the waterway, enhance water quality, and establish vital habitats for local wildlife.
The project originated as part of a broader response to severe flooding within the 7-square-mile Bee Branch Watershed, home to more than half of Dubuque's population. Previous flash floods had caused extensive damage to roughly 1,300 homes, local businesses, and municipal infrastructure. To address the crisis, the city daylighted the Bee Branch, a creek that had been buried in a storm sewer for approximately a century. Reintroducing the waterway to the surface allowed natural features to be integrated directly into local flood mitigation efforts.
Before the floating islands were placed in the creek, developers created four prototype designs varying in size and shape. Ultimately, the 14 completed structures were built to function as miniature replicas of the natural archipelagos found along the Mississippi River. The primary framework utilized thousands of recycled water bottles, which were paired with native plants and selected pieces of driftwood to establish year-round utility for local species. Fencing was also installed around the vegetation to protect new growth from local waterfowl.
A system of stainless-steel cables anchors the floating structures to the creek bed. This flexible anchoring arrangement allows the islands to shift position naturally in response to changing water levels and flow directions. Partially funded through grants and donations, the entire project cost $176,000, according to the report.
Beyond their visual integration into the landscape, the islands perform key ecological tasks. Their physical construction interrupts wave energy, which helps minimize erosion along the creek's edges. By acting as barriers that slow moving water, the structures allow suspended sediment to settle, keeping the water clearer.
Furthermore, the integrated plants absorb nutrients such as nitrogen and phosphorus. Preventing these excess nutrients from traveling further downstream helps mitigate broader ecological challenges in the Mississippi River and the Gulf of Mexico. Beneath the water's surface, the floating architecture and plant roots offer surfaces for biofilms—microorganisms that assist in breaking down pollutants. The submerged roots also supply shelter for fish and juvenile aquatic species, while insects and crustaceans utilize the vegetation as part of the local food web. Above the water, birds rely on the islands for resting spots and potential nesting areas.
Maintaining nature-based infrastructure requires ongoing effort, as demonstrated by the Dubuque project. The islands undergo regular checks to evaluate their buoyancy, health of vegetation, and the condition of their anchoring systems. A 2019 inspection showed that most plants were thriving, though some required replacement following animal interference, and portions of the protective fencing needed repairs.
Dubuque's experience highlights the importance of careful site selection, native plantings, durable materials, secure anchoring, and consistent upkeep for municipalities considering similar nature-based interventions. What began as a component of a municipal flood-control initiative has evolved into a functioning element of urban ecology, demonstrating how modern flood infrastructure can successfully incorporate natural habitats.