200750700 - Crumble-Crete Habitat Revegetation and Stability Blocks - Development of degradable bank protection/reveg block to provide temporary stability during recovery of natural bank-stabilizing vegetation.

Sponsor: WDFW and CRITFC

Short description: Hollow blocks will be formed (trials of straw, gravel and cement) and installed in a ditch bank, filled with soil and planted with riparian vegetation. Block strength, transport, durability and rate of root development in the fill soil will be monitored.

Location: Columbia Plateau province, Yakima subbasin

Budgets: FY08: $25,498 | FY09: $2,240

Primary species:
Anadromous: Anadromous Fish


ObjectiveDescriptionSubbasin planStrategies
1. Form Test Blocks Hollow 2ft x 2 ft x 6 ft blocks will be formed from nine differing mixes, composed of gravel combined with three concentrations of cement and three concentrations of straw. Four blocks of each mixture will be formed for the purpose of testing for minimum strength requirements: the blocks must be strong enough to allow for handling, transport and placement. Yakima Creating more natural stream bank stabilization structures rather than rip rap, ecology blocks or concrete. Supports Table 12 Strategy-Riparian Restoration; Table 15-Channel Stability; Yakima Plan 4-5, adaptive management and research.
2. Perform Strength Testing The cured test blocks will be subjected to lifting and dropping from the height of three inches. Mixes that produce more than one broken block will be considered unsuitable for large, machine-placed applications. Of the mixes that are considered suitable, the blocks will be tested to failure using a ------ stress test. Yakima "
3. Pour Blocks for Field Testing Of the mixes that met the strength requirement,additional blocks will be poured to total ten blocks of each. These will be cured and spray-painted over half of a long face before being transported to the field site. Painting of half the exposed face will aid in monitoring surface deterioration rates. Yakima "
4. Install & Backfill Test Blocks at Field Site The ditch banks at the field site will be excavated by 2 ft and lined with single rows of the test blocks. Excavated bank material will be used to backfill the hollow blocks. Fill material will be gently tamped with the bucket of the backhoe or excavator. Yakima "
5. Vegetative Fill Material Cuttings from local woody riparian plant sources will be planted through the fill material in 5 blocks from each mixture; in the other 5, nursery-raised plants in of the same species composition and density will be planted. All the vegetation will be thoroughly watered at the time of planting. Yakima "
6. Maintain Plantings The water level in the ditch will be maintained at a level no more than one foot below the top of the blocks. Weeds will be controlled in three out of five of each treatment. Yakima "
7. Monitoring Prepare brief written report of results for BPA and for general availability. Submit project for presentation at Yakima Basin Science and Management Conference as well as other meetings and technical workgroups with Yakama Each block will be labelled with a code indicating the mixture used and vegetative treatment. Photo points will be established for each block. Vegetation photos that include height indicators (e.g. a visible survey rod) will be taken in the first week of May and November. Photos indicating the rate of deterioration of the block surface will be taken concurrently. Also, at the time of photo monitoring, water quality (i.e., pH) measurements will be taken upstream of the project area and within three inches of the downstream face of each treatment to ascertain whether the deterioration of the blocks affects water quality. Yakima "
8. Measure Preliminary Results At the end of the initial test period the most representative test block for each treatment, based on average vegetative growth, will be identified. Vegetation will be exhumed, and root development measured. The strength of the block will be measured, in place, using the same stress test applied to the test blocks. Yakima "
9. Summarize & Report Preliminary Results Preliminary findings will be submitted in a report that summarizes vegetative response and changes in strength of the blocks that are an expected result of degradation of the organic component of the mixes. Yakima "



  • ISRP: Unranked
  • Council: Not fundable
  • BPA: Not fundable