ScholarWorks at University of Montana

Rapid population growth in Missoula County has spurred a rise in residential and commercial property development. A portion of this growth impacts Missoula County’s watercourses and floodplains. To better understand the implications of this development, Missoula County floodplain administrators require baseline information concerning bank stabilization projects and floodplain structures. The Montana Department of Environmental Quality and the United States Environmental Protection Agency jointly funded a project designed to establish a bank stabilization project database for five Missoula County watercourses. Bank stabilization structures on the Clark Fork River, Bitterroot River, Blackfoot River, Lolo Creek, and Nine Mile Creek were inventoried and evaluated during the summer of 1999. Data describing 215 bank stabilization projects were collected over the 121 river miles comprising the study area. Bank projects stabilized a total of 29 river miles and varied by age, material, size, project need, and adjacent land use. The floodplain manager will use the inventory database in conjunction with other information as a tool to educate landowners concerning the hazards of floodplain development.

County floodplain regulations are meant to prevent property from being built in harm’s way, prevent damage to property caused by others’ actions, and allow streams and rivers to convey floodwaters naturally. They can also have the added benefits of protecting river health and natural beauty.

Proposed amendments to County floodplain regulations would prohibit new levees and limit new rip rap and other bank armoring. Rip rap and levees, while providing a short-term localized fix, often increase bank erosion and flood damage to nearby properties. In addition these structures harm aquatic and terrestrial habitats.

Missoula County discourages bank stabilization projects unless they are part of a larger project that addresses the cause of the instability. Cosmetic bank stabilization projects may increase instability of nearby property and harm stream health by limiting natural stream migration. However, the County recognizes that misguided historic actions have contributed to bank instability and may need to be addressed. For example, channelization of the upper Clark Fork and Lolo Creek by railroads and highways has caused very unstable banks as the watercourses try to regain length. Increased sedimentation and loss of riparian vegetation on Ninemile Creek have resulted in a shallow, braided stream with unstable banks and decreased aquatic habitat. Where bank stabilization efforts seem needed to address these historic problems, the County encourages the use of “softer” bank stabilization techniques that can slow bank erosion, increase stream complexity and allow for long term bank revegetation.

Floodplain regulations can prevent some types of flood damage by ensuring that new bridges do not cause constrictions or limit sediment transport. Another preventative measure is to prohibit large scale clearing of native streamside vegetation, which can help prevent bank failure during high water.

Longer term goals of property protection and river restoration include building setbacks from streams and rivers, restoring old meanders of the Clark Fork cut off by transportation facilities, removing a mile-long levee on the Bitterroot, and restoring lower Grant Creek from its current “ditched” state.

The Missoula Mill of the Smurfit-Stone Container Corporation has been actively pursuing improvements in the pulping and papermaking process for many years. Particularly over the last fifteen years, the mill has made great strides in reducing contaminant loading of the process wastewaters. During this fifteen year period, many small individual improvements have added up to an impressive reduction in Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), Color, Nutrients (Nitrogen & Phosphorus). In the future, the Missoula Mill anticipates further reductions in these parameters as the mill pursues compliance with new regulations for the Pulp and Paper Industry, commonly known as the “Cluster Rules”. This presentation demonstrates the successes that the Missoula Mill has achieved in its ongoing efforts to reduce pollution. Many people have been involved in the process that has led to these achievements.

Arriving online in October 1999, Missoula Measures is an internet-based, Missoula County-specific information center, designed to assist efforts to maintain and build a healthy, sustainable community. Initiated by local government, this online resource grew out of a set of community indicator reports produced in 1997-98 by the Health Department, Office of Planning and Grants, and the City of Missoula. Missoula Measures is a tool that reflects and integrates the ongoing work and thinking of hundreds of people, and makes this information strategically more available to others for various purposes. Measures can be thought of in two ways: we measure what we value and we strive to take effective measures to work on what is important to us. In addition, this tool works to link and serve clusters of people with interests in particular Measures topics. A key goal is for the Measures to be used and useful.

Individual Measures topics are divided into three interrelated realms: environment, economy and social measures. Several Measures are watershed-related. There are currently more than 70 topics addressed.

The Missoula Mill of Smurfit-Stone Container discharges treated process water to the Clark Fork River near Frenchtown, Montana. Annual monitoring (1956 - present) of macroinvertebrate indicated river quality, is an integral part of the Missoula Mill's environmental protection effort. Quantitative riffle benthos samples from ten sites (study reach = 22 miles) are taken during August. Impact is determined using control vs experimental comparisons of community descriptors including the biometrics subsets used in the calculation of the Montana Biological Integrity Index. Study results show significant background (upstream mill) enrichment in incremental amounts over the period 1960 through the late 1980's, presumably a product of growth in the Clark Fork, Blackfoot, and Bitterroot drainages. Mill related impact throughout this same period, also expressed as enrichment was limited and localized to the zone of initial dilution. Recent study results (1995 - 1999) generally show either continuation, or a slight decline, in overall enrichment of the system relative to the Missoula Mill's treated effluent.

Rattlesnake Creek is a tributary of the Clark Fork River that flows through parts of western Montana and through Missoula. Currently, an effort is underway to increase spawning habitat for bull and westslope cutthroat trout in the Clark Fork drainage. One proposal in this effort includes the modification or removal of the Mountain Water Company dam on lower Rattlesnake Creek that currently blocks fish passage. The removal or modification of this dam would open miles of prime spawning habitat. However, the Clark Fork River is known to be contaminated with Myxobolus cerebralis, the causative agent of salmonid whirling disease. The presence of this parasite in the Clark Fork River has lead to concerns that removal/modification of the dam would allow the parasite to spread into the upper reaches of Rattlesnake Creek, endangering the wild trout populations already established there. Therefore, the objective of this study was to survey the upper portions of Rattlesnake Creek for the presence of the aquatic oligochaete, Tubifex tubifex. T. tubifex is an obligatory host for M. cerebralis and the parasite cannot be transmitted to trout in its absence. An earlier, cursory study by another investigator did not detect T. tubifex in the Rattlesnake, so we conducted a more comprehensive survey of the creek for this oligochaete. Further, these worms were screened for the presence of M. cerebralis triactinomyxons (TAMs; stage of parasite that infects trout).