FLOW REGULATION AND RESTORATION OF FLORIDA KISSIMMEE RIVER

Channelization of the Kissimmee River in central Florida destroyed or degraded most of the fish and wildlife habitat once provided by the river and its floodplain wetlands. Between 1984 and 1989 a demonstration project was conducted to evaluate the feasibility of restoring the river's biological resources. Reintroduction of flow through remnant river channels improved river channel habitat diversity and led to favourable responses by fish and invertebrate communities. However, results indicated that more complete restoration of biological attributes will require the re-establishment of historical inflow characteristics. Owing to the flood control regulation schedule of its headwater lakes, current river discharge regimes are pulse-like, include extended periods of low or no flow, and have high and low flow periods which are out of phase compared with typical seasonal patterns that occurred before channelization. These flow characteristics will preclude effective river restoration by contributing to chronic low dissolved oxygen regimes and repetitive fish kills, interfering with fish reproduction and limiting floodplain inundation. Simulation modelling was used to develop a modified headwater lakes regulation schedule which re-establishes season flow patterns, smooths discharge peaks and maintains base flows for a greater portion of the year. Implementation of the new schedule, combined with extensive canal backfilling, will lead to discharge and stage characteristics that meet established criteria for achieving ecosystem restoration goals.