The Portneuf River Watershed Project: Targeting Sustainable Water Quality Improvements

The Portneuf River Watershed Project: Targeting Sustainable Water Quality Improvements submitted by: Three Rivers Resource Conservation & Development (RC&D) Council, Inc. in cooperation with Shoshone-Bannock Tribes Idaho State University Idaho Department of Environmental Quality City of Pocatello Bannock County J.R. Simplot Company Rapid Creek Research, Inc. Portneuf Soil and Water Conservation District Idaho Association of Soil Conservation Districts Idaho Soil Conservation Commission USDA-Natural Resources Conservation Service Portneuf Marsh Valley Canal Company Hydrologic Unit Code: The Portneuf River Watershed 8-digit HUC level, 17040208 Impaired Waters: Idaho’s 2002 303(d) list includes five impairments in the Portneuf River Watershed. Impairments in order of decreasing river kilometers impaired include unknown causes (3 water body segments impaired; 408 km), sediments (10 segments; 321 km), pathogens (4 segments; 72 km), bacteria (4 segments; 51.2), and nutrients (2 segments; 34). Contact Information: Mr. Kent Rudeen, Chairperson Three River RC&D Council 1551 Baldy Ave. Suite 4 Pocatello, ID 83201 Phone: (208) 237-4628 ext 102 Fax: (208) 237-3412 Tax Exempt Status: 501(C)(3) Website: www.portneufriver.org Additional material about the watershed can be found at the Portneuf River Ecosystem Project (PREP) site: http://www.isu.edu/bios/prep/ 1 ABSTRACT Here we propose to implement on-the-ground projects and innovative research and outreach in the Portneuf River Watershed. This work will benefit from use and operation of a state-of-the-art and locally supported continuous monitoring network that spans over 80 river kilometers and provides near-real time information on water quality. The very existence of this network enabled us to target the most impaired regions of the watershed and focus restoration efforts accordingly. Our proposal targets Marsh Creek, the largest tributary to the Portneuf and one of Idaho’s 22 most degraded streams, and a reach of the Portneuf River on the Fort Hall Indian Reservation impaired from livestock grazing. We will also evaluate innovative practices to mitigate urban impairments associated with the storm sewer system and a channelized river reach. A multifaceted outreach program which will include the development of a dynamic watershed information system that offers new opportunities for more integrated internet-based interaction will be used to disseminate our findings. PROJECT NARRATIVE 1.0 Watershed Characterization The Portneuf River sub-basin encompasses 3,434 km2 of Bannock, Bingham, Caribou, and Power counties in southeast Idaho. Its 156-km length is fed by 927 km of perennial streams, 1,453 km of intermittent streams, and approximately 225 km of excavated canals. Agriculture is the dominant land use (range and crop land make up 48% and 33% of the sub-basin, respectively); forest and urban lands comprise only 13% and 3% of the sub-basin (Krajewski 2002). The river originates and is fed by high mountain streams on the Fort Hall Indian Reservation. At the reservation boundary it flows into Chesterfield Reservoir, below which water is withdrawn for irrigation. Municipal wastewater inputs enter the Portneuf from downstream municipalities; the largest of which is the City of Pocatello (Figure 1). The largest tributary to the Portneuf River is Marsh Creek, draining nearly one third of the watershed. Multiple segments of the Portneuf River and Marsh Creek have been listed as impaired for sediment, pathogens, bacteria, and nutrients (IDEQ 2005). Still, the Portneuf watershed provides many opportunities for recreation including hiking, biking, swimming, paddling, soaking in natural mineral hot springs (www.lavahotsprings.com), skiing, snowshoeing, snowmobiling, hunting, and fishing. Improving the health of the watershed is critical to sustaining these recreational opportunities. While it shares problems common to many rivers in the U.S., the Portneuf River is unique among rivers in Idaho and the Pacific Northwest. As one of its most distinguishing traits, it originates and ends on a Native American Reservation (Fort Hall Indian Reservation), but the majority of the Portneuf’s path is through non-reservation lands. On and off the Reservation, it meets the water needs for more than 72,000 people. The multijurisdictional setting of the Portneuf River creates an interesting and challenging sociopolitical water management situation that can serve as a model for problem solving in other multijurisdictional watersheds. The Portneuf River has been impaired by land use and hydrologic alterations that have caused increased concentrations of ions and sediment and changes in thermal conditions. Although these impairment problems are not unique, the Portneuf River merits significant, targeted study because of the way these impacts cross jurisdictional boundaries (i.e. reservation, cities, counties, school and watershed districts) creating a sense of ‘our’ versus ‘their’ problems which serve to hinder our ability to address these impacts. This proposal will build on a substantial existing collaborative effort. The Greater Portneuf River Watershed Partnership includes representatives from industry, educational institutions, scientists, and government agencies (City, County, State, Tribal, and Federal) established to facilitate monitoring of water quality and ecological conditions in the Portneuf River. The group has met regularly for over 5 years to examine and disseminate information on local surface and groundwater issues. Participation by Idaho State University (ISU) has resulted in increased research and participation of graduate, undergraduate, and K-12 students. We have established a state-of-the-art and locally supported continuous monitoring network that spans over 80 river kilometers and provides near-real time information on water quality that is accessible to the public. These efforts have already helped break down barriers of misunderstanding in the watershed. The work proposed here will make significant progress towards our ultimate goal of a healthy sustainable watershed by tackling documented agricultural and municipal water quality problems through an array of proven management approaches and the implementation of innovative techniques which have no borders. 2.0 Project Need The Portneuf River is a major tributary to the Snake River that has documented water quality problems that affect aquatic life and threaten the benefits provided by this shared and culturally significant resource. Seasonally, the river experiences elevated sediment loads associated with agricultural activities in upper parts of the watershed. For example, agricultural land use along Marsh Creek has led to water quality conditions that have placed it among the worst 22 streams in Idaho for soil erosion problems, and listing as the number one priority stream affected by agriculture (Krajewski 2002). Impairments described in Marsh Creek are present to a lesser degree in other portions of the watershed on and off the Fort Hall Indian Reservation. On the upper Portneuf River, within the Reservation, water quality impairments and habitat degradation have been attributed to livestock in riparian habitats. The Shoshone-Bannock Tribes Water Quality Program conducted monitoring on two 200 m reaches of the Upper Portneuf in 2005 as part of a Reservation-wide bioassessment project. E. coli concentrations ranged from 326-816 CFU/100 ml, and Wolman Pebble Counts indicated that fines (< 2.5mm) made up over 90% of the particles within the stream’s wetted width. The Tribes’ modified Stream Macroinvertebrate Score for the lower of these two reaches was 44, below the median score for other Reservation streams (51.5), and the richness of Ephemeroptera, Plecoptera, and Trichoptera was much lower than the average for the Idaho Basin Bioregion (Grafe 2002). Although municipal lands represent a small area of the watershed (2.6%, or 90 km2), we have documented seasonal impacts from municipalities on water quality. Like many cities, Pocatello has a system that directs untreated storm water into a local river. During an 11-day period encompassing much of the spring runoff in 2004, one stormwater drain was estimated to empty approximately 15,500 lbs of sediment into the Portneuf (Inouye unpublished). 3 In 1968, a 9 km flood control project of the U.S. Army Corps of Engineers created a concrete stream channel with vertical side walls along a roughly 2.5 km reach in the City of Pocatello (USACE 2006). Monitoring over the past four years has shown that concentrations of E. coli at the downstream end of the channel have regularly exceeded IDEQ’s primary and secondary contact standards during the summer. Thus, significant channel modifications combined with low flows resulting from drought and irrigation have led to the regular reoccurrence of elevated levels of bacterial pathogens in the Lower Portneuf River. These examples of impairments in the Portneuf River illustrate the complexity of water quality and quantity issues in our watershed. Idaho’s 2002 303(d) list of impairments has been supplemented by findings from locally supported continuous monitoring, the Greater Portneuf Water Resource Partnership (GPWRP), and ongoing research at ISU. The continuous monitoring network provides water quality data from multiple locations at high temporal resolution. We have developed empirical relationships between optical turbidity, suspended sediment concentrations, and particulate phosphorus (Inouye and Ray 2002) allowing for the expanded measurement of other

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