SCH Number 2020060469

Project Info

Title

Hope Valley Restoration and Aquatic Enhancement (Lake or Streambed Alteration Agreement No. 1600-2020-0082-R2)

Description

Project Site 1: Restoration techniques will mimic an abandoned oxbow feature by excavating an approximately 2.5ft deep by 14ft wide trench behind a failing riverbank and filling it with live sod blocks, willow stakes, and live shrub transplants. The trench construction will avoid disturbance of mature vegetation and will maintain a minimum 3 to 4ft setback from the top of the riverbank. Approximately 500 cubic yards of soil will be excavated and hauled off-site. Meadow sod blocks will be salvaged prior to excavation and reinstalled over the side slopes and bottom of the excavated floodplain bench during the revegetation phase. A temporary irrigation system will be installed to minimize plant stress and erosion by means of slow water delivery with low impact nozzles. The irrigation system will remain in place until November 15. The work at Project Site 1 will temporarily impact approximately 0.14 acre of palustrine wet meadow and 0.01 acre of riverine habitat. Project Site 2: The restoration work’s primary focus at Project Site 2 is to update previous restoration work by providing additional stability to divert stream energy from scouring behind the current log crib structure. This will be accomplished by installing slash to the ends of the reach. Slash will consist of locally-sourced conifer and willow cuttings and will be weaved in between vertically-placed 8in x 10ft slash anchor logs. The slash anchor logs will be embedded 7ft into the ground using an auger to drill 8in holes for placement. Live willow stakes, installed down to or near groundwater, will also be placed vertically within the end of reach project areas. Live stakes will be installed along the reach at an average spacing of 5ft. The ends of the reach will be regraded slightly to maintain stable bank conditions and facilitate placement of slash anchor logs. Approximately 9 cubic yards of soil will be excavated during the bank regrading. Excavated soil will be dispersed in adjacent upland areas. Soil dispersal will not exceed a depth of 6in. Soils will be hand raked to further disperse material. The work at Project Site 2 will temporarily impact approximately 0.01 acre of riverine habitat.

1 documents in project