The U.S. Army Corps of Engineers, Seattle District (Corps) has prepared, pursuant to the National Environmental Policy Act, a draft Integrated Detailed Project Report and Environmental Assessment (DPR/EA) for the Lower Dungeness River Ecosystem Restoration Project near Sequim, Clallam County, Washington. Ecosystem problems in the study area stem primarily from degradation of riverine processes including channel formation, sediment transport, organic matter exchange, food web support, and wood recruitment. Levees constructed along the reach effectively disconnect the main channel from the historic floodplain. A Corps levee built in 1963 was the first and longest levee constructed in the area disconnecting approximately 410 acres of floodplain, side channel and distributaries from the river. In response to the Corps levee, two private dikes were built on the opposite bank, disconnecting approximately 150 additional acres. Levee construction adjacent to the main channel has impacted the riverine processes that create and sustain habitat, leading to coarser sediments on the bed, elevated gravel bars, less woody debris, and fewer stable pools. The levees also cut off side channels and result in higher velocities and depths during floods.
AUTHORITY
The proposed project is a separable element of the specifically authorized project, Puget Sound and Adjacent Waters Restoration, WA, (PSAWR) authorized by Section 544 of the Water Resources Development Act of 2000 (Public Law 106-541, December 11, 2000), which authorizes implementation of critical restoration projects in Puget Sound and its contributing watersheds. The Federal interest in this separable element of the PSAWR program stems from its intent to restore habitat for Endangered Species Act (ESA)-listed species, habitat which has been impacted by a Corps levee.
PURPOSE AND NEED
The purpose of this study is to evaluate restoration opportunities related to the lower Dungeness River and to recommend a plan to restore degraded riverine processes and habitat. The need for the proposed Federal action arises from the significant degradation of natural processes that sustain the ecological functions of the lower Dungeness River. Specifically, disconnection of the river from its historic floodplain has degraded in-channel and off-channel habitat for Federally-listed fish species, as well as the associated riparian zone that historically enhanced the riverine habitat while also providing habitat for mammals, raptors, songbirds and other wildlife.
PROPOSED ACTION
The proposed action would modify the Corps levee in the reach to reconnect the Dungeness River to 110 acres of floodplain, bounded to the west by the main channel and to the east by Meadowbrook Creek, a groundwater fed stream in a paleochannel of the Dungeness River (Figure 2). Approximately 2,600 feet of the existing Corps levee would be removed, and the material utilized to rebuild a 5,700 foot long realigned levee away from the channel, just west of Meadowbrook Creek. Engineered log jams, large cottonwood livestakes, and anchored large wood clusters would be installed to modulate hydraulic forces with the intent of accelerating development of channels suitable for fish, and to reduce avulsion risk tied to the elevated (aggraded) condition of the existing river bed and site topography. Native plants would be planted to control erosion and accelerate habitat recovery where soils are disturbed due to construction.
Approximately 1,800 linear feet of Towne Road would be rerouted landward of the lower, wetter portion of the site. Towne Road would be allowed to flood periodically (approximately every 2-5 years on average). A bridge would be installed where Towne Road crosses a new back channel, allowing high water to pass under the road to a lower section to the east, and allowing fish entering the lower area to escape when high water recedes. The bridge would also allow terrestrial mammals to avoid the road when traversing the site.
Since levee realignment would result in a segmented levee (i.e., a gap would be left between the realigned levee and existing levee to remain), an access road located about a mile south of the levee would be included as part of the project to ensure adequate emergency access (Figure 3). The access road would follow the alignment of an irrigation pipeline that is planned to replace an existing irrigation ditch.
Unavoidable adverse effects of the proposed project actions include: (1) noise disturbance to wildlife and home owners in the vicinity of operating heavy machinery during construction; (2) pollutant emissions from heavy machinery during construction; (3) disruption of local traffic in the project vicinity during construction; (4) the potential for initial turbidity during the connection of the newly constructed side channel to the Dungeness River; and (5) the filling of approximately 1.2 acres of existing wetland and excavation of about 9.2 acres of wetland to create side and back channel habitat. Levee modification resulting in periodic overbank flooding, enhancement of the remaining wetlands, expected conversion of additional upland to wetland over time, and plantings and recruitment of native woody species would compensate for the initial wetland loss by increasing the overall habitat complexity and function of the site.
Given the temporary, localized, and minor nature of the anticipated adverse effects, the Corps has determined that the proposed levee repair and mitigation project would not result in significant adverse environmental impacts.
EVALUATION
The Corps has made a preliminary determination that the environmental impacts of the proposal can be adequately evaluated under the National Environmental Policy Act through preparation of an environmental assessment (EA).
The Corps will coordinate with Federal agencies to ensure careful consideration of fish and wildlife resources. For projects that intend to restore fish habitat, agencies can accomplish their ESA consultation requirements by complying with a programmatic biological opinion for habitat restoration. To fulfill the requirements for consultation under ESA, the Corps will prepare a Specific Project Information Form (SPIF) and submit this form under the Habitat Restoration Programmatic Biological Opinion (2008). Construction would not begin prior to completion of the ESA consultation process.
The Corps has prepared a draft 404(b)(1) analysis, included as an attachment to the DPR/EA (Appendix I). Receipt of Water Quality Certification under Section 401 of the Clean Water Act and a Coastal Zone Consistency Determination for the proposed project would be attained during the detailed design phase and prior to construction.
The Corps has coordinated its environmental review impacts on cultural resources for NEPA with its responsibilities to take into account effects on historic properties as required by Section 106 of the National Historic Preservation Act (1966). The Corps has determined and documented the area of potential effect (APE) for both direct and indirect effects, as required by 36 C.F.R. Part 800.4 of the regulations implementing Section 106. The APE includes the 110-acre levee setback footprint (the half-mile of levee to be removed), the new levee alignment and the proposed one-mile emergency road that will connect the southern end of the newly setback levee. The Washington State Historic Preservation Officer (SHPO) agreed with our determination of the APE on August 17, 2011. Previous cultural resources surveys indicated that two historic structures and one prehistoric archaeological site are located within the APE. The two historic structures were mitigated under a memorandum of agreement (MOA) executed on November 15, 2012. The SHPO agreed on January 15, 2015 with our determination of adverse effect for prehistoric archaeological site (45CA650). Mitigation of adverse effects to site 45CA650 will be subsequently resolved through a separate MOA with the SHPO, Advisory Council on Historic Preservation (ACHP), and the Indian tribes (Jamestown S’Klallam Tribe and Lower Elwha Klahham Tribe).
Avoidance measures and reduction of impacts would take the form of on-site biological and cultural resources monitoring, the implementation of best management practices (BMPs) during construction, and scheduling construction to avoid potential impacts to fish and wildlife species.
PUBLIC REVIEW PROCESS
Any person who has an interest or that may be affected by the restoration project may request a public hearing. The request must be submitted in writing to the District Engineer within the comment period of this notice, and must clearly set forth the following: the interest that may be affected, the manner in which the interest may be affected by this activity, and the particular reason for holding a public hearing regarding this activity.
The decision whether to conduct the project will be based on an evaluation of the probable impact on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefit, which reasonably may be expected to accrue from the proposal, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal will be considered; among these are: conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, flood plain values, land use, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, consideration of property ownership and, in general, the needs and welfare of the people.
The Corps invites submission of factual comment on the environmental impact of the proposal. Comments will also be considered in determining whether it would be in the best public interest to proceed with the proposed project. The Corps will consider all submissions received before the expiration date of this notice. The nature or scope of the proposal may be changed upon consideration of the comments received. The Corps will initiate an Environmental Impact Statement (EIS), and afford public participation opportunities attendant to an EIS, if significant effects on the quality of the human environment are identified and cannot be mitigated.
Submit comments to this office, Attn: Environmental and Cultural Resources Branch, no later than February 18, 2015 to ensure consideration. In addition to sending comments via mail to the address on page 1, comments may be e-mailed to melissa.l.leslie@usace.army.mil. Requests for additional information should be directed to Ms. Melissa Leslie at 206-764-6587, or the above e-mail address.