Approximately 63% of the total Blue River Basin can be characterized as urban (USACE 1974.) Furthermore, thiswatershed is one of the most rapidly developing urbanizing areas in the Kansas City region, and urbanization threatens to further impair the river, damage flood control projects and harm substantial financial investments in the Lower Blue River.The Blue River runs through the heart of Kansas City and has quietly directed much of the development of the city south of the Missouri River. The lower Blue River, which extends from its mouth at the Missouri River south to Brush Creek, is surrounded by approximately 8,000acres of its watershed. This reach of the Blue River has been channelized by the US Army Corps of Engineers, primarily for flood mitigation. Land use along the first four miles of the river is industrial with many salvage yards and similar operations within the original flood plain.
Further south and upstream, industrial development continues to follow the river, giving way to commercial and residential development, as well as large areas of open space. Approximately 30 percent of this area is impervious. In this lower part of the watershed, there are approximately 28,000 people (2005 data) who anecdotally are primarily ethnic and minority communities. (Combined SSS and CSS area data averages from the Kansas City, MO Water Services Department Overflow Control Plan, January 30, 2009.)
South of Brush Creek to 95th Street, the middle Blue River remains channelized until E. 63rd
Street within this 12,300-acre portion of the watershed. This area has a population of approximately 32,500 people and there is a large industrial park along its western bank, south of 63rd Street. Large tracks of residential development lie to the west and adjacent to the river to the east. South of here the Blue River travels through Swope Park, Kansas City’s largest urban parkland. The residential areas west and east of Swope Park consist of primarily minority and ethnic communities. To the south of Swope Park, the area along the Blue River again becomes primarily industrialized along the river with residential areas radiating beyond.
The Upper Blue River Watershed lies primarily in Johnson County and contains roughly 6,300 (only 9% of the total watershed) acres of parks and public open space ranging from small neighborhood parks to large regional parks. Mid-America Regional Council predicts a 40% growth in population for Johnson County by 2010 (Johnson County Planning and Development 2002.) Currently, farms and agriculture dominate the remainder of the Upper Blue River Watershed; however, agricultural uses are declining as urban development expands.
Blue River Water Quality Impaired and Threatened -
Water quality conditions vary in this urban Watershed. Much of the headwaters of the watershed is sparsely developed and contains high-quality natural resources and intact stream buffers. In the middle and lower river areas, water quality, stream bank stability and habitat are being impacted by human activities, and land uses including agriculture, residential and commercial development, and roads and highways.
Stream assessments indicate that water quality is somewhat better in the Kansas streams, upstream of the wastewater treatment plants. Impervious surfaces are a byproduct of urbanization and are important indicators of watershed hydrology. Using typical assumptions from the Natural Resource Conservation
Service, it is estimated that the Negro Creek sub-watershed is approximately 19 percent impervious and the Blue River main stem sub-watershed is about eight percent impervious. It is estimated that roughly half of the northern portion of the Upper Blue River watershed will exceed 25 percent imperviousness within 15 years.
The Blue River basin is subject to flood flows most frequently in the spring and early summer. Subsequently, the combination of the shape, topography, and fairly dense soils of the watershed, as well as urbanization, are contributing factors toward high concentrations of runoff. Flood conditions are aggravated by a high number of bridges which restrict flows and reduce the capacity to pass excess water. The continuing encroachment of development will create additional obstructions to exacerbate flooding within the watershed. Consequently flooding will worsen as the watershed develops unless steps are taken to mitigate the effects of urbanization (USACE 1974.)
According to the USGS, urbanization, point-source discharges, urban run-off, physical stream conditions and complex water-quality processes influence water quality in the Blue River basin. While the upper reaches remain largely unaltered, changes are occurring with increasing pressure from urbanization. Downstream of Johnson County’s Blue River Wastewater Treatment Plant (WWTP), about 50 percent of Blue River base flow is effluent during normal conditions and up to 95 percent during droughts. Base flows contain significant pesticides, nutrients, TSS and pharmaceuticals. Pesticides, nutrients and organic compounds increase significantly during rain events due to non-point pollution. A number of watershed streams are impaired and several Total Maximum Daily Loads (TMDLs) have been developed. The Blue River main stem in Kansas and Camp Branch, Coffee Creek, and Wolf Creek are impaired from fecal coli form bacteria. This portion of the Blue River in Kansas is also listed as impaired for elevated nutrients and oxygen demand. And Chlordane is an issue in both Kansas and Missouri (Missouri Department of Natural Resources 2006; Kansas Department of Health and Environment 2006.)