In lieu fee mitigation plan



Download 7.62 Mb.
Page12/21
Date31.03.2018
Size7.62 Mb.
#43992
1   ...   8   9   10   11   12   13   14   15   ...   21

Adaptive Management Plan


The EBR Mitigation Project seeks to meet the specific mitigation obligations for WSDOT and others while at the same time being consistent with natural floodplain processes and addressing the recovery plans of the Lower Cedar River Basin. Adaptive management is necessary to address these issues as the site develops over time.

Due to the dynamic floodplain processes, some project elements or performance measures may require more time to develop, may develop differently than intended or may be impacted by natural processes such as floods. If monitoring results indicate that performance standards are not being attained for any monitoring year, additional adaptive management actions will be required.

As described in the Adaptive Management and Contingencies Planning in Appendix O of the Program Instrument (King County, 2012), “Adaptive management plans included with mitigation plans will necessarily lack specific measures to address underperformance, since the type of underperformance will not be known at the time the Mitigation Plan is developed. Specific corrective measures will be developed if and when underperformance details become clear. Any and all adaptive management measures will be appended to the Mitigation Plan and the IRT will review and comment on any additions or amendments to Mitigation Plans.”

In general terms, adaptive management is a systematic process in which modifications to a compensatory mitigation plan, including monitoring, maintenance, and contingency plans, are made based on what has or has not been effective. Adaptive management is a feedback loop in which monitoring information is used to determine how site management may be adjusted if the project’s performance standards are not being met. Monitoring is a critical feedback in the adaptive management system that is to be used at the site as shown below.



Generalized version of the adaptive management system to be used at the Project site.

Reproduced from Naiman and Latterell (200517).

An adaptive management plan, for the purpose of this document, consists of scenario-planning in which a list of plausible problem scenarios are developed, conditions of concerns are described and time-bounded, and a progression of potential actions are proposed to address each problem scenario. In short, it is a planning step that helps to determine whether there is a good chance that additional construction work may be necessary after the project has been completed in order to make the project function properly or to address risk (e.g., as identified in the Safety Inspections).


Table 13 Examples of adaptive management strategy options in response to various scenarios.

Numbered strategies represent progressive steps that could be taken as needed to respond to each scenario. Please note that many of the adaptive management actions listed below would require permits before the work could be completed.



Scenario

Description

Progression of Adaptive Management Strategies

1

Left bank levees or revetments are threatened or damaged

  1. Assess and document risk

  2. Consult with IRT

  3. Emergency repairs

  4. Others to be specified by design team

2

Blocking logjams form in the project site

  1. Use existing policies (e.g., natural wood policy) to address risks from instream wood; may result in no action, establish or improve egress or portage routes outside the site, or a take-out reach upstream. In rare cases, may result in wood repositioning, cutting, or river closure18

3

Wetland performance standards unmet

  1. Consult with IRT and appropriate agencies

  2. Change in plant community mosaic or minor regrading of site

  3. Establishment of additional compensatory wetland areas

4

Canopy cover performance standards unmet

  1. Install plants at higher density

  2. Substitutions of plant species

5

Noxious weeds performance standards unmet

  1. Least invasive removal (e.g. hand- or mechanical removal)

  2. Herbicide applications implemented as part of an integrated pert management approach

  3. Extension of performance period

6

Fish stranding in backwater channel

  1. Consult with IRT and appropriate agencies

  2. Minor grading of outlet, placement or relocation of LWD

  3. Major regrading of channel or conversion of backwater channel into a side channel

7

Wood structure function performance standards unmet

  1. Consult with IRT and appropriate agencies

  2. Adjustment of existing wood structures, including the incorporation of additional small wood into the structures

  3. Placement of additional wood structures within project area

8

Placed wood retention performance standards unmet

  1. Consult with IRT and appropriate agencies

  2. Installation of additional wood within the project area

  3. Installation of additional wood outside of the project area

9

Floodplain woody habitat structure performance standards unmet

  1. Consult with IRT and appropriate agencies

  2. Adjustment of existing woody habitat structures, including the incorporation of additional small wood into the structures

  3. Placement of additional structures within project area

11

River deposits logs on the ELJ

  1. Consult with IRT and appropriate agencies

  2. Use existing policies (e.g., natural wood policy) to address risks from instream wood; may result in no action, establish or improve egress or portage routes outside the site, or a take-out reach upstream. In rare cases, may result in wood repositioning, cutting, or river closure19

10

Rock deflector is destabilized or does not function as intended

  1. Consult with IRT and appropriate agencies

  2. Re-position rocks to improve or restore function

  3. Consider alternative means to accomplish the intended outcome

11

Human use/encroachment

  1. Consult with IRT and appropriate agencies, including Sheriff

  2. Install signage to discourage damaging uses

  3. Make access more difficult (various options)

King County retains the flexibility to implement adaptive management actions in consultation with the IRT that are consistent with the larger mitigation objectives. For example, floodplain wetlands may experience both erosion and/or deposition due to flooding on the Cedar River. This in turn affects the hydrology and native plant communities appropriate for the setting (scenario 4 above). While replanting of species, or substitution of species will be required, these minor adaptive management actions do not require consultation with the IRT and will be implemented and reported on in required monitoring reports. If monitoring results indicate that performance standards are not attainable due to changed environmental conditions or natural processes within the floodplain, such as excessive deposition, erosion or channel migration, King County will consult with the IRT on appropriate adaptive management actions and/or revisions to the performance measures with the intent of meeting the mitigation obligations without compromising natural floodplain processes or implementing actions adverse to the recovery plans of the Lower Cedar River Basin.




  1. Download 7.62 Mb.

    Share with your friends:
1   ...   8   9   10   11   12   13   14   15   ...   21



The database is protected by copyright ©ininet.org 2024
send message
    Main page
main stem