Urban expansion alters surface runoff due to increased impervious surfaces across the landscape. To address this urban hydrological issue, many regulatory agencies now require developers to reduce the impacts of urbanization on watershed hydrology. Florida regulations, for example, require developments to not exceed the pre-development runoff levels. Due to their well-established hydrological efficacy, stormwater ponds (SWPs) are one of the most common stormwater management approaches for new development. These de novo ecosystems are particularly common in Florida, where there are >75,000 SWPs statewide. The construction of SWPs doesn’t happen in a vacuum, though, as the expansion of urban areas has come at the cost of a variety of terrestrial and aquatic ecosystems, including wetlands. For example, there was a 33% loss of wetland area in the Tampa Bay watershed between 1950 and 2007 while the construction of artificial aquatic ecosystems offset 75% of this wetland loss. While SWPs are clearly not identical to natural wetlands, they are capable of providing some similar functioning, including nutrient processing, carbon sequestration, and habitat for wildlife. It is unclear, however, how this reorganization of the waterscape from natural wetlands to de novo ecosystems affects the functions being provided. Quantifying the functions that SWPs (and other de novo ecosystems) provide is important to improve the design and management of these human-derived ecosystems, maximizing their benefits to society. But it also important to balance these functional gains with those lost due to wetland loss. By combining empirical field measurements and literature values with historical remote sensing imagery, we can estimate the magnitude of wetland-SWP transitions from an areal extent and quantify the effect of these transitions on regional biogeochemical dynamics. This approach will provide an understanding of how urban development has influenced downstream water quality over previous decades. Combining this approach with future land use projections, we can identify the potential impacts of future development and develop strategies to protect ecosystem functions while still allowing for responsible urban expansion.