The primary goal of the Fort Hall Habitat Restoration project is to restore, enhance, and protect Fort Hall Indian Reservation (Reservation) streams so they can support native fish populations at near historic levels. The Fort Hall Bottoms area provides a range of ecosystem services important to the Shoshone-Bannock Tribes, which includes  sustaining populations of Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and other native fish. The range and distribution of Yellowstone cutthroat trout have been impacted in many tributaries of the Snake River by competition with other salmonids and by habitat degradation. Streams on the Reservation have been negatively affected (i.e. loss of riparian vegetation, down cutting, and lateral scouring of stream banks) by a variety of sources, including livestock grazing, American Falls Reservoir construction and operations, and the 1976 Teton Dam collapse.  Damage to stream banks from years of unrestricted grazing continues to be a problem on Reservation streams. Rapid flooding and drafting of American Falls Reservoir in conjunction with seasonal freeze-thaw cycles is a cause of stream bank failures on lowland Reservation streams.  Negative impacts from stream bank failures include, but are not limited to:  widened channels, a reduction in riparian vegetation and in stream cover; increased summer water temperatures, and deposition of fines on critical spawning and rearing substrates.  Stream restoration will continue to be the focus of the Fort Hall restoration work on the Bottoms.

Habitat restoration will remain the primary focus for the Fort Hall project in this contract.  Restoration work in this contract will address the Doug's Sloping reach.  Design and engineering work for this project was initiated in the previous contract (77111 REL 10).

Doug's Sloping Project Status and Schedule

Project work in this contract will focus on construction on the Doug's Sloping Phase 1 restoration work in Spring Creek. The design of this project was contractually initiated in September 2018 with the intention of commencing construction in summer and/or fall of 2019. Delays were incurred in the development of this project’s design because of the federal government’s shutdown in late 2018 and early 2019. The government’s delay further delayed this project with respect to: inclement seasonal weather, survey acquisition and associated contracting. Engineering designs are nearly finalized and will be submitted to BPA for ETS review prior to the start date for this contract.

The Doug's Sloping restoration project has been developed to be constructed in two phases to accommodate the project’s physical size (footprint), available funding, and associated funding schedules. The proposed phases may require further refinement to accommodate available funding and appropriate construction windows. Ideally, this project’s phase size and/or funding structure and can be refined to maintain a construction start date of late summer/early autumn for Phase 1.

FY2019
Construction Phases:

The Doug's Sloping project is currently designed to be constructed in two phases: Phase 1 will be done in fall 2019 and Phase 2 will be done in the subsequent contract (fall 2020) . Phase 1 generally involves reconstructing the downstream reach and will create the foundation for the upstream improvements that will be done in Phase 2. Phase 2 will enhance the upstream reach and the side channel/beaver pond complexes east and west of the mainstem of the stream. The design will use similar restoration techniques as were applied to the Diggie Creek restoration project in previous contracts.

Phase 1 (Downstream Reach)

Key aspects of the Phase 1 (downstream reach) design include:
1)    Generally maintaining the pattern/location of developing pools and riffles.
2)    Reducing the average bankfull width from about 150-feet to approximately 60- to 70-feet wide. This will be accomplished by:
a.    Filling in the relatively shallow/muddy areas along the steep, eroded, vertical stream/floodplain banks with “Causeway Banks” and/or “Slash and Fill”.
b.    Installing Causeway Banks along the pools along the bends in the stream. Causeway Banks consist of a dense, interwoven matrix of trees backfilled with gravel ballast excavated from the neighboring pools. Trees range in size from small to large trees (with and without rootwads) and include “Slash”, which consists of branches and brush. Relatively straight trees will be driven through the Causeway Banks as piles to provide additional structural integrity. Concrete anchors and boulders from the previous “Doug’s Sloping” project will be added to these banks to help counteract scour, movement and floating. Causeway Banks extend at least 8-feet down into the channel bank to accommodate scour and sustain deep pool habitat.
c.    Installing “Slash and Fill” along the shallower, straighter, riffle-dominated sub-reaches. Slash will be also be placed in an interwoven matrix to provide structural integrity. Smaller wood piles will also be driven into the existing channel bed to added integrity. Gravel excavated from the downstream pools will be used as ballast where gravel is readily available. Where gravel is not available, Slash and Fill areas will be backfilled with the sandy loam soil from the nearby high, steep, eroding, vertical banks and uplands.
d.    The Causeway Banks and Slash and Fill areas will be installed to the bankfull water surface elevation and planted with emergent wetland vegetation.
3)    Riffles are located at the downstream end of each proposed pool. The stream configuration (gradient, cross-section and pattern) of the proposed stream has been refined such that the riffles utilize the existing gravel for vertical stability without the need for additional gravel/cobble reinforcement. (The median size of the existing gravels are generally in the 1.0- to 2.0-inch range and will accommodate trout spawning well.)
4)    The aforementioned potential “avulsion” near the confluence of the existing western side channel will be transformed into an instream pool flanked with a Causeway Bank. This feature accommodates and stabilizes the anticipated avulsion while creating complex instream habitat at the side channel confluence.
5)    An “Oxbow Pond” will be created on the eastern side of the stream’s floodplain in the location of an existing instream pool. This will be located across the stream from the proposed pool in the avulsion area. This pond will be hydraulically connected to the stream and will provide off channel habitat and flood refugia for the fish and wildlife species previously mentioned. Installing this pond in the relatively deeper, existing pool reduces the amount of fill that would otherwise be placed in the floodplain bench.
6)    The riffle located at the downstream reach/upstream reach interface (Phase 1/Phase 2 interface) has been designed to naturally accommodate the transition from the wider, gently-sloped upstream reach into the narrower, slightly-steeper downstream reach. Like to other riffles in this project, gravel/cobble bed reinforcement is not required at this riffle.

Work in this contract will also focus on addressing ISRP deliverables outlined in the most recent project review, community outreach, and out-year planning.