Rivers Case Studies/Examples

Kissimmee and Cockermouth Case Studies

Original length of Kissimmee River channel

103 miles

Size of Kissimmee River Floodplain

approximately 40000 acres and up to 3 miles wide

Reason for channelisation proposal

Prolonged flooding after hurricanes in 1940s impacted local towns

Project initiated in response to 1940s flooding

Central and Southern Florida Project, initiated by US Army Corps of Engineers

Floodplain species pre-channelisation

24 fish species, 4000-5000 waterfowl, alligators, much native wetland vegetation

Timeline for C-38 Canal

Between 1962 and 1971 the meandering river was straightened

C-38 Canal dimensions

56 miles, 27-91m wide, up to 10m deep

Flow controls installed in C-38

5 water control structures (similar to locks) installed

Main environmental impact of channelisation

Over 19500 acres wetlands lost

Decline in wildlife populations

Waterfowl populations dropped by 90%, bald eagles dropped by 70%, fish species dropped by over 50%

Impact on water quality

Increased pollutants and sediments due to disconnection to floodplain, oxygen levels dropped by 50% causing increased algal blooms

Cost of channelisation

Approximately $29 million USD

Restoration timeline

Grassroots efforts advocated before completion of channelisation, 1972 restoration discussions began, 1992 Water Resources Development Act, construction began in 1992, officially completed in 2021

Restoration project goals

Aimed to restore 44miles of meanders and 20000 acres of wetlands

Kissimmee restoration cost

Approximately $980 million USD

Environmental positives of restoration

Increase in dissolved oxygen, return of native vegetation, enhanced biodiversity, and re-establishment of natural hydrological patterns

Stakeholders for channelisation

USACE, Congress, SFWMD local residents, construction firms

Stakeholders against channelisation

FDEP, EPA, Audubon society, Friends of the Everglades, local residents

Cockermouth confluence

The River Cocker meets the River Derwent

Cockermouth major flooding pre-management

End of November 2009 - prolonged heavy rainfall led to saturated ground