Title
Grant Creek Flood Control & Stream Naturalization Project
Abstract
Grant Creek flows south into the Missoula Valley from the foothills of the Rattlesnake mountains northwest of the City of Missoula. The creek’s headwaters are in national forest and private ranchlands. However, residential and commercial development has grown rapidly where the creek approaches I90. To protect this development, the creek has been confined by a berm, restricting it from much of its former floodplain. The creek flows under I90 in a culvert and then onto the floor of the valley where much of the creek’s flow is lost to infiltration into its alluvial fan. Below I-90 the creek does not flow much of the year. The creek generally follows its historic path but has been straightened and channelized. From West Broadway to the Clark Fork Floodplain, Grant Creek flows across flat agricultural land that is undergoing rapid development. The creek flows near the Mullan Trail subdivision near Mullan Road, where high groundwater from leaking irrigation ditches is thought to contribute to flooding of the subdivision. The creek passes under Mullan Road in a culvert and flows through ranchland on the Clark Fork floodplain to the Clark Fork. Culverts at W. Broadway, Mullan Trail and to a lesser extent I-90 are fish passage barriers.
Missoula County seeks to develop a project that will reduce flooding, improve fish habitat and passage, and improve recreational & aesthetic opportunities. HDR has designed a project to address these goals.
Start Date
1-4-2005 1:00 PM
End Date
1-4-2005 3:00 PM
Document Type
Poster
Grant Creek Flood Control & Stream Naturalization Project
Grant Creek flows south into the Missoula Valley from the foothills of the Rattlesnake mountains northwest of the City of Missoula. The creek’s headwaters are in national forest and private ranchlands. However, residential and commercial development has grown rapidly where the creek approaches I90. To protect this development, the creek has been confined by a berm, restricting it from much of its former floodplain. The creek flows under I90 in a culvert and then onto the floor of the valley where much of the creek’s flow is lost to infiltration into its alluvial fan. Below I-90 the creek does not flow much of the year. The creek generally follows its historic path but has been straightened and channelized. From West Broadway to the Clark Fork Floodplain, Grant Creek flows across flat agricultural land that is undergoing rapid development. The creek flows near the Mullan Trail subdivision near Mullan Road, where high groundwater from leaking irrigation ditches is thought to contribute to flooding of the subdivision. The creek passes under Mullan Road in a culvert and flows through ranchland on the Clark Fork floodplain to the Clark Fork. Culverts at W. Broadway, Mullan Trail and to a lesser extent I-90 are fish passage barriers.
Missoula County seeks to develop a project that will reduce flooding, improve fish habitat and passage, and improve recreational & aesthetic opportunities. HDR has designed a project to address these goals.