In lieu fee mitigation plan



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Monitoring


  • Monitoring: Defined here as the act of making observations and/or measurements for the purpose of detecting problems, demonstrating compliance with environmental permits and mitigation requirements, demonstrating compliance with performance standards, and evaluating project performance for the sake of determining project performance and improving future projects. Takes the form of site visits, regulatory, mitigation, and effectiveness monitoring (pre- and post-project), and facility and public safety inspections (e.g. built facilities and placed wood), and submitting monitoring reports.

The EBR Mitigation Project will be monitored for 10 years after installation to document performance, prescribe maintenance needs, and guide adaptive management actions as the site develops over time and responds to natural processes inherent in a dynamic floodplain environment. The Mitigation Monitoring Plan is outlined here, as is the Safety Inspection Plan – another form of monitoring.

Mitigation monitoring will be performed and documented in a monitoring report 1, 2 (scour structure only), 3, 5, 7, and 10 years after construction. Since scour structure construction will be completed in Year 1, after site construction, the first year of scour structure monitoring will occur in Year 2. Year 2 monitoring will only include the scour structure. Subsequent monitoring years (3, 5, 7, and 10) will combine all monitoring elements. Mitigation monitoring documents the achievement of the project’s mitigation-related performance standards. Monitoring reports will be submitted to all members of the IRT by the month of April in the year following the formal monitoring activities conducted 1, 2 (scour structure only) 3, 5, 7, and 10 years after site construction.



Protocol for determining wetland area:

Wetland areas exhibit wetland hydrology and a dominance of hydrophytic vegetation.



Protocol:

  1. Conduct wetland delineations in both left and right bank mitigation areas in Years 5 and 10, in accordance with the 1987 Corps manual and the Regional Supplement for the Western Mountains, Valleys, and Coast Region (ERDC/EL TR-10-3). This will include delineation of boundary lines on the ground showing the hydrophytic and upland vegetation determined using paired sampling plots using the Dominance Test for hydrophytic vegetation unless the Dominance Test is negative and all of the Criteria in Appendix B of the Regional Supplement (p. 136) are met. The delineation report will include, at a minimum, a map showing the wetland boundaries on the left and right banks, locations of data plots, and copies of all data sheets.

Protocol for determining floodplain area:

  1. After delineating wetland areas, the remaining areas can be considered floodplain if they meet one of the three following criteria:

    1. It is part of the wetted or active (unvegetated) channel of the Cedar River mainstem river that has formed as the result of channel migration or widening after the project was completed.

    2. It has the attributes of one or more of these features: permanently connected channels (not the mainstem), flood channels, islands, bars and natural levees, spring brooks, ponds, scour holes, permanently or seasonally-disconnected side flows, and active accretion areas such as point bars and shelves of recent origin (Stanford 2006).

    3. It lies within in the valley bottom area capable of flooding (Stanford 2006) when discharge at Landsburg is > 3,570 cfs, which exceeds a 2-year recurrence interval (RI) flood. The flood elevation is approximately 99 feet on the right bank and 96 feet on the left bank, based on pre-project observations.

  2. Monitor in Years 5 and 10.

Protocols for estimating native plant density:

  1. Use a 20 m x 2 m belt transect to estimate plant density.

  2. Count all planted trees and shrubs within 1 meter of the central transect, on either side of the line.

  3. Monitor in Year 1.

Protocols for estimating percent crown cover of native trees and shrubs:

  1. Crown cover of native trees and shrubs will be measured towards the end of the growing season but before leaf drop (e.g., mid-August to mid-September).

  2. Cover of native trees and shrubs will be calculated as the reciprocal of Crown-Free Projection or CFP (Bonham 2013). CFP = (S/T)*100, where S is the number of open-sky sightings and T is the total number of observations of the canopy made with the use of a two-way leveled periscope (a GRS densitometer) pointed toward the sky or the ground.

  3. Collect plant occurrence data at vertical intercepts located at each meter-mark along each transect, for a total of 20 sample points per transect, or 60 per planting zone. At each interval, a “hit” on a species is recorded if a vertical line at that point would intercept the stem or foliage of that species. Only one “hit” is recorded for a species at a point even if the same species would be intercepted more than once at that point.

  4. The total number of “hits” for each species along the transect is then determined. The result is a list of species and their frequencies of occurrence along the line (Mueller-Dombois and Ellenberg 1974; Tiner 1999). Cover will be reported as percentages, not cover classes.

  5. Monitor in Years 3, 5, 7, and 10.

Protocol for measuring the area of channel margin habitat for salmonids:

  1. The created backwater on the left bank is not to be counted toward the performance target for channel margin habitat.

  2. River margin habitat (i.e., edge habitat) is defined as a slow-water (<0.15 m/s) unit in or adjacent and connected to the wetted mainstem channel12). In the as-built condition, this will exist as bars and bank edges, but after channel adjustment and migration, these areas may also include side channels and backwaters that have formed in areas that were formerly mainstem river channel or vegetated landforms (Beechie et al. 2005, Bisson et al. 2006).

    1. Bars: Slow-water channel unit located where the channel meets a shallow, gently-sloping shore.

    2. Banks: Slow-water channel unit located where the channel meets a deep, nearly vertical shore.

    3. Backwaters: Slow –water, partially enclosed channel unit along a mainstem bank at the downstream end of a disconnected floodplain channel or secondary channel.

    4. Side channels: Either channelized flow of emergent hyporheic groundwater in flood channels, or channel units connected to the mainstem at both ends but containing less than half the discharge.

    5. Map extent and distribution of low velocity (<0.15 m/s) edge habitat on both sides of the mainstem river, excluding the left bank backwater channel and hydromodified banks, when discharge at Renton is 800-1,200 cfs (USGS 12119000; Renton).

    6. Use a Trimble GPS to map two lines for each slow-water area; the edge of water (inside line) and visible current shear line (outside line), where flow velocities begin to exceed the specified threshold. Locate the velocity break with a flow meter and validate at least every 10 meters, unless a shear line is visible.

    7. Do not map hydromodified edges (those along levees).

    8. Do not map edge areas that are less than 0.5-1.0 meter in width.

  1. Analyze edge habitat data by summing the total area of edge habitat.

  2. Monitor in Years 3, 5, 7, and 10.

Protocol for documenting hydraulic engagement of Type B large wood structures (right bank logs anchored to boulders):

  1. Establish photo points to document whether the wetted channel contacts Type B wood structures as designed (large logs along the right bank margin and anchored with boulders).

  2. Take photos at each photo point when flows are between 800-1,200 cfs (USGS 12119000; Renton). Photos should be taken once annually (e.g. in spring), after the annual peak discharge has occurred.

  3. Monitor in Years 1, 3, 5, 7, and 10.

Protocol for estimating retention rate for placed large wood:

  1. Locate and count installed snags, ‘jams’, Type C (embedded) logs, and ‘spanner’ logs in the project area on both banks during leaf-off conditions for maximum visibility.

  2. Tally recruited wood – pieces deposited by the river - that are at least as large as Type C logs (16-30 inch diameter, 35 feet long).

  3. Analyze large wood survey data by comparing observed large wood abundance to placed large wood abundance as recorded in the approved as-built report.

  4. Monitor in Years 3, 5, and 10.

Protocol for evaluating scour pool functions of ELJ:

  1. In each monitoring year, visually assess the characteristics of any scour pool associated with the ELJ to determine whether it has formed an eddy scour pool or lateral scour pool (Bisson et al. 2006, p. 35).

    1. Eddy Scour Pool: ‘A slow-water channel unit created by scour that forms a depression in the streambed. The pool results from a large flow obstruction along the edge of the river, usually a large wood deposit, rock outcrop, or boulders. The pool is located on the downstream side of the structure and is roughly proportional to the size of the obstruction.’

    2. Lateral Scour Pool: ‘A slow-water channel unit created by scour that forms a depression in the streambed. The pool occurs where the channel encounters a flow obstruction near the edge of the stream (i.e., bedrock outcrops, boulders, large wood, or gravel bars). Forms next to or under large, relatively immoveable structure such as accumulation of logs. Water is deepest adjacent to the streambank containing the obstruction and shallowest along the opposite bank.’

  1. Measure residual pool depth and pool area using TFW (1999) protocols for the ELJ-formed pool, and the two reference pools:





Jones Rd. Logjam Reference Pool

2014 Residual Depth: 5.1 ft.

2014 Area below the residual depth contour: 2,116 ft2


Lower Landslide Reach Reference Pool

2014 Residual Depth: 2.4 ft.



2014 Area below the residual depth contour: 2,452 ft2



  1. Measure the dimensions of over-water cover associated with each of the three scour pools. If it is unsafe to take measurements, visually estimate the area to the nearest 5 ft2 and document with photos.

  2. Monitor in Years 2, 3, 5, 7, and 10.

Protocol for documenting hydraulic engagement and structural integrity of the ELJ:

  1. Establish photo points to document whether the wetted channel contacts the ELJ.

  2. Take photos at each photo point during the late summer or early fall low-flow period when flows are between at approximately 200 cfs (USGS 12119000; Renton).

  3. The ELJ is ‘hydraulically-engaged’ if some portion of ELJ or racked wood contacts the wetted channel, unless the low-flow channel has migrated away from the ELJ or a gravel bar forms beside the ELJ. Neither outcome constitutes a failure to meet this standard.

  4. Visually locate and inspect the condition of the key logs—those necessary for structural integrity— to see if any are missing or broken. Take photos of the structure to verify and document conditions.

  5. Monitor in Years 2, 3, 5, 7, and 10.

Protocol for documenting use of the ELJ by adult salmon:

  1. Use an underwater video camera to document the presence of adult salmon at the ELJ-formed scour hole and at the two reference pools.

  2. Survey each jam until adult salmon are observed at each pool, or up to three times between mid-September and mid-October, whichever is less.

  3. Monitor in Years 2, 3, 5, 7, and 10.

Protocol for assessing the area of off-channel habitat on the left bank:

  1. Map extent and distribution of wetted backwater habitat at the left bank project area when discharge at Renton is 800-1,200 cfs (USGS 12119000; Renton).

  2. Monitor in Years 5 and 10.

Protocol for evaluating accessibility of left-bank off-channel habitat to juvenile and adult fish:

  1. Measure the depth of the connection point to the mainstem in spring, after the occurrence of the annual peak discharge. Take the measurement when discharge at Renton is approximately 200 cfs (USGS 12119000; Renton).

  2. Monitor in Years 1, 3, 5, 7, and 10.

  3. When discharge at Renton is approximately 200 cfs ((USGS 12119000; Renton) typical of low-flow conditions in later summer), measure the length of the backwater channel that is inundated, to verify that at least half the length is wetted up to the confluence of the two forks of the backwater.

  4. Use an underwater video camera to document fish presence during low-flow conditions (200 cfs (USGS 12119000; Renton); in August or September) in the backwater channel, and in any closed depressions. At a minimum, video-sample half of the wetted channel length and all of the closed depressions. Review video to estimate the number (and if possible, species identity) of fish observed in each location.

  5. Monitor in Years 1, 3, 5, 7, and 10.

Protocol for determining compliance with plant invasive species standards:

  1. In Years 1-10, inspect the entire site thoroughly to verify that Washington State-listed or King County-listed Class A weeds designated for control by the County Weed Board and non-native knotweeds identified on the King County noxious weed list are absent. If they are present, initiate appropriate control. One purpose is to be pro-active and identify new infestations while they are easier to control.

  2. In Years 1-10, quantify combined ground cover (total cover of the target vegetation on an area of ground; Bonham (2013)) of weeds using the same 20 point-intercept plots used to measure cover of native shrubs and trees. Ground cover of the weeds will be measured as the number of points that intercepted one of these weeds (i.e., above or below the tape).This approach allows weed cover to be quantified separately for Right and Left Banks and for each planting area. Determine whether the combined ground cover of the following plants exceeds 10 percent in any mitigation credit area:

    • Non-native blackberries (Rubus armeniacus and R. laciniatus),

    • Scotch broom (Cytisus scoparius),

    • Thistles (Cirsium arvense, C. vulgare, Carduus nutans, and Onopordum acanthium),

    • Purple loosestrife (Lythrum salicaria),

    • Yellow-flag iris (Iris pseudacorus),

    • English and Atlantic ivy (Hedera helix and H. hibernica),

    • Butterfly bush (Buddleia davidii),

    • Field bindweed (Convolvulus arvensis) and morning glory/hedge bindweed (Convolvulus sepium),

    • Any other Class B or C weeds designated for control by King County.




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