Permit Application Public Notices

The United States Congress authorizes the U.S. Army Corps of Engineers to regulate activities that may impact wetlands and waters of the United States. This authority is granted and defined under Section 10 of the Rivers and Harbors Act of 1899 and Section 404 of the Federal Water Pollution Control Act Amendments of 1972, also known as the Clean Water Act.

Public involvement is a key element of the Corps’ permit review process. During an application review, the Corps considers the views of other federal, state and local agencies, Native American tribes, interest groups, and the general public. The results of this careful public interest review are fair and equitable decisions that allow reasonable use of private property, infrastructure development, and growth of the economy, while offsetting the authorized impacts to the waters of the United States.

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Portland District
Published Dec. 28, 2023
Expiration date: 1/26/2024

Application for Permit

Issue Date: December 27, 2023
Expiration Date: January 26, 2024
30-Day Notice                                                                                                                                                                                                                              U.S. Army Corps of Engineers No: NWP-2022-494


Interested parties are hereby notified the U.S. Army Corps of Engineers, Portland District (Corps) has received an application for a Department of the Army permit for certain work in waters of the United States, as described below and shown on the attached drawings. The Corps is soliciting comments on the proposed work.

Wallowa Lake Irrigation District (WLID)
Attention: Dan Butterfield, President        
65196 Dobbin Road
Joseph, Oregon 97846        
Telephone: (541) 263-0320

Applicant’s Agent:
McMillen, Inc.
Mort McMillen, Executive Vice President
1471 Shoreline Drive, Suite 100
Boise, ID 83702        
Telephone: (208) 342-4214

Location: The project site is located at the Wallowa Lake Dam, in Wallowa Lake, the Wallowa River, and Silver Lake Ditch near Joseph, Wallowa County, Oregon. The site is in Section 5, Township 3 South, Range 45 East. Latitude and Longitude: 45.335211° North, 117.222663° West.

Waterway: Wallowa Lake, Wallowa River, and Silver Lake Ditch. The location of the ordinary high water mark (OHWM) shown on the project drawings have not yet been verified by the Corps. If the Corps determines the boundaries of the waters are substantially inaccurate a new public notice may be published.

Project Purpose: The applicant’s stated project purpose is to rehabilitate the Wallowa Lake Dam to correct dam safety hazards that were identified in 1996 and to improve fish passage. Completion of the project would allow the WLID to restore the capacity of the dam and reservoir to operate at a full pool elevation and ensure the dam is rehabilitated consistent with Oregon Water Resources Department dam safety standards. Operation of the dam and reservoir at a full pool elevation would provide for flood protection, potable water supply, irrigation water supply, water conservation, fish passage, improved fish and wildlife habitat, continued recreational use, future low head and low impact hydropower production, and economic stability.

Project Description: The Wallowa Lake Rehabilitation project would include the rehabilitation of existing structural components (dam and low-level outlet conduits) and the construction of two new spillway bays and gates, steel hoist structure, and a fish sorting facility. The applicant would permanently discharge up to 3,691 cubic yards (cy) of concrete, soil, rock, and metal fill material within an area measuring 7,856 square feet (sq. ft.) below the OHWM of Wallowa Lake; up to 53 cy of fill material within an area measuring 675 sq. ft. below the OHWM of the Wallowa River; and up to 112 cy of fill material within an area measuring 527 sq. ft. below the OHWM of the Silver Lake Ditch for the construction and rehabilitation of dam structures. The applicant would temporarily discharge up to 890 cy of fill material within an area measuring 8,586 sq. ft. below the OHWM of the Wallowa Lake, and up to 25 cy of fill material within 168 sq. ft. below the OHWM of the Wallowa River to isolate and dewater the work area during construction. 

Fill proposed below the OHWM


Aquatic Resource

Area (sq. ft.)


Time fill is to remain


Dam Stability Section

Wallowa Lake




Concrete, Steel

Construction Fill

Wallowa Lake




Soil, Rock

Perm Road and Fill

Wallowa Lake





Perm Road Fill

Wallowa Lake





Intake Structure

Wallowa Lake




Concrete, Metal, Rock

Retaining Wall

Wallowa Lake




Concrete, rock

Upstream Cofferdam

Wallowa Lake




Rock, Metal

Bypass Pipe

Wallowa Lake





Temp Dam Access

Wallowa Lake






Wallowa River




Rock, Concrete

Plunge Pool

Wallowa River




Rip Rap

Downstream Cofferdam

Wallowa River





Splitter Box

Silver Lake Ditch




Rock, Metal, Concrete



Rehabilitation of existing structures:
To upgrade the dam to meet current structural dam stability design codes, the applicant would add a new concrete section to the upstream side of the existing dam. The concrete section would be approximately 16-feet-wide extending from the upstream face of the dam and across the width of the main channel. The new concrete would be poured (cast-in-place) with a straight upstream face rather than matching the existing curved dam face. The new top of dam elevation would be 4,390 feet above mean sea level (MSL) and would be tied into the north and south abutments at the same elevation. The existing concrete apron in front of the dam would be removed and the new concrete poured on the exposed and prepared foundation materials. New guardrails would be installed on the top of the dam, providing safe conditions for the dam operators. When the dam rehabilitation is complete, the existing dam would be fully encased on the upstream and downstream sides with new concrete that would provide a fully functional and durable structure.

The applicant would rehabilitate and maintain the existing low-level outlet conduits for water releases from the reservoir. There are five existing outlet conduits, each measuring 16 sq. ft. with a sluice gate mounted on the upstream side of the dam. Each conduit would have a 42-inch-diameter steel pipe placed inside the existing concrete conduit and a new fabricated stainless-steel gate mounted near the entrance to the conduits. Vents would be installed on the downstream side of the gates to ensure adequate aeration is provided. 

A 5-foot-diameter penstock is located on the south abutment of the dam. The applicant would modify the structure in order to provide the water supply for the fish trap structure located on the south abutment. New hydraulic cylinder gate operators would be installed on each sluice gate. 

The City of Joseph water intake is located just east of the dam and would not be disturbed during construction activities. The water supply pipe extends down the channel leading to the dam, then passes through the south dam abutment to the south of the existing penstock. 

After installation of the cofferdams, the applicant would field locate the existing City of Joseph 14-inch-diameter water lines upstream and downstream of the dam within the confines of the cofferdam work areas. The applicant would core drill through the existing dam and place a new section of 18-inch-diameter steel water line. The applicant would connect the new section to the existing lines within the existing work and excavation areas. Work on the piping would be coordinated with the City of Joseph and occur outside of the high demand summer months. Well water would be utilized as needed during planned outages during construction. 

Construction of new structures
New structures would include the spillway, energy dissipator structure, fish passage components (intake structure, fish screens, bypass pipes, release gates, fish trap and transport facility).

The applicant would construct a new gated spillway consisting of a two-bay system with two (2) approximate 20-foot-wide by 12-foot-high vertical roller gates, including hoists and motors. The spillway crest would be set at elevation 4,378 feet MSL. The spillway would be designed with a standard ogee crest and a maximum discharge of approximately 2,800 cubic feet per second (cfs). New training walls would be required on both sides of the spillway to contain the spillway flow. 

For the energy dissipating structure, flows exiting the spillway would enter a stilling basin with a short reinforced concrete flip bucket (approximately 3-feet-long) located on the downstream end of the basin. The stilling basin would be approximately 40-feet-wide and 40-feet-long. When releasing larger flows from the spillway, the flow would be “flipped” to an existing plunge pool located approximately 60 feet downstream of the stilling basin downstream sill.

The applicant would construct new downstream fish passage structures that would consist of a new intake tower and fish screens, a mid-level fish bypass pipe, and an upper-level fish release gate and bypass pipe. The new intake structure would exclude fish from entering the existing Silver Lake Ditch, allowing the fish to pass through the dam through one of three bypass locations: (1) the low-level outlet conduit, (2) mid-reservoir bypass pipe, or (3) upper-level gate and bypass pipe. The bypass pipes would be supported by steel or concrete piers founded on the new dam concrete surface (located above the OHWM). 

The new fish passage facility would incorporate a small-scale fish surface collector if determined to be beneficial for anadromous juvenile fish migration. The surface collector would be located within the lake, east of the original natural outlet,
and consist of an exclusion net, surface collector with pumped attraction flow, bypass pipe routed to the dam, and electrical power source routed form the north bank of the reservoir. The bypass pipe would be attached to the mid-reservoir release pipe entrance constructed as part of the dam rehabilitation. The surface collector, if implemented, would be provided primarily for the sockeye salmon juvenile fish outmigration.

The applicant would construct an adult fish collection trap and transport facility above the OHWM of the Silver Lake Ditch on the south abutment of the dam.

As part of the overall construction work, the intake structure and screens at the dam are designed to screen the Silver Lake Ditch flows. The existing wooden flume would be removed from the connection to the dam. A new concrete flume section would be constructed within the same footprint as the existing Silver Lake Ditch wooden flume section. The new concrete flume would include adjustable stoplogs located on the river side of the flume. The stoplogs could be adjusted to return flow back to the river that passes through the new intake structure located on the upstream face of the dam. 

Pre-construction activities: 

The applicant would dewater a portion of the Wallowa River and Wallowa Lake prior to construction using cofferdams and wells. A 48-inch-diameter bypass pipe would divert lake flows through the construction area. The bypass pipe would extend from an upstream cofferdam to the face of the existing dam where it would be connected to the existing 5-foot-diameter penstock. Once the construction is complete, the applicant would remove the cofferdams and bypass pipe, and water would be returned to the main channel and lake.

All contractor staging and laydown areas would be located in upland, on WLID property, in the open field located north of the dam and Wallowa Lake. The existing access ramp into the channel upstream of the dam would be improved to provide a long-term stable access point to the debris booms. 

The applicant would install supersack cofferdams for dewatering a section of Wallowa Lake near the upstream face of the dam, and a section of the Wallowa River immediately downstream from the dam. The upstream cofferdam would have a minimum height of 8 feet. For the upstream cofferdam, the applicant would install a temporary steel vault (42 sq. ft.) at the lowest point of the cofferdam and used as an intake structure for a bypass pipe.

The applicant would install a 48-inch-diameter bypass pipe that would divert lake flows through the construction area and would be designed for a maximum flow rate of 100 cfs, the maximum diverted flow during the typical winter outage period. The bypass pipe would be tied into the existing steel penstock and the Wallowa Lake and Wallowa River would be dewatered from the temporary upstream cofferdam to the penstock outlet. Following construction, the applicant would grade the lake upstream of dam to 4,354 feet MSL. The applicant would coordinate the installation of the upstream cofferdam with the City of Joseph. The downstream cofferdam would consist of a sandbag system with a minimum height of 3 feet.

Demolition, removal of structures, and the preparation of other structures for rehabilitation: 

The project would require the demolition and removal of existing gate operators, wood platforms, a portion of the concrete spillway and walls, wood flume, form ties, and other small dam components (guardrails, electrical boxes, etc.). No blasting or rock fracturing techniques would be used for demolition. Demolition of concrete would likely occur by mechanical or hydraulic methods with onsite collection of removed materials. The applicant would remove approximately 8- to 12-inches of concrete from the downstream face of the dam, and clean and remove any damaged concrete from the upstream face of the dam. The applicant would remove the first 50 feet of the existing Silver Lake Ditch wooden flume replace it with a concrete structure. Standard concrete forming and placement would take place in dry conditions. The existing wood log booms located in the Wallowa River upstream of Wallowa Dam would be removed prior to construction and retained for use post construction activities. The existing log boom shore anchors would be maintained during construction.

Dredged Material Testing: The proposed dredged material will be evaluated in accordance with the Sediment Evaluation Framework for the Pacific Northwest (SEF). The interagency Portland Sediment Evaluation Team (PSET) implements the SEF for the Corps Portland District. The PSET will determine if sediment testing is required for this project. Project sediments may require physical, chemical, and/or biological testing to support the permit application evaluation. The PSET will evaluate the applicant’s sediment testing results and determine if project sediments are suitable for unconfined, aquatic disposal and exposure. 

Mitigation: The applicant proposes to avoid and minimize impacts from the project by rehabilitating portions of the dam structure to minimize the amount of demolition required. This would limit the volume of concrete debris and reduce the amount of habitat disturbances within the project area. Excess concrete excavation materials would be taken to a nearby concrete plant for recycling. An erosion and sediment control plan would be implemented. Materials excavated and stockpiled would be covered or seeded to prevent water or wind erosion and to abate dust. Erosion control measures may include hydroseeding, straw mulch, silt fences and sandbags. Equipment fueling and maintenance would be conducted at least 250 feet from waterways and inspected regulatory for leaks. 

The applicant did not propose compensatory mitigation in the permit application. The Corps will determine the type and amount of compensatory mitigation necessary to offset environmental losses from the proposed project.

Drawings: Twenty-five (25) drawings are attached and labeled Corps No. NWP-2022-494. Copies of this public notice, which have been mailed or otherwise physically distributed, feature project drawings in black and white. The electronic version features those drawings in color, which we think more accurately illustrates the proposed project. To access the electronic version of this public notice, go to the Portland District Regulatory website at and under Regulatory Pages select Permit Application Public Notices.

Additional Information: The structural design would be stamped by a State of Oregon Registered Structural Engineer. The Design Document Report to be submitted with the stamped drawings and specifications would contain an outline of the Structural Design Criteria including, but not limited to the criteria established in Federal Energy Regulatory Commission Chapter III, Guide to Gravity Dams and Corps Engineer Manual (EM) 1110-2-2100 Stability Analysis of Concrete Structures and EM 1110-2-2107 Design of Hydraulic Steel Structures for the spillway gates and other hydraulic steel structural elements. All calculations and contract deliverables are reviewed internally by similarly qualified structural engineers and would be included with the Design Document Report. The documents would be submitted to Oregon Dam Safety for review and comments. 

Authority: The proposed project will be evaluated under the following:

Section 404, Clean Water Act (33 U.S.C. 1344), for discharge of dredged or fill material into waters of the United States.

Clean Water Act Section 404(b)(1) Guidelines: The described discharge will be evaluated for compliance with guidelines promulgated by the U.S. Environmental Protection Agency under authority of Section 404(b)(1) of the Clean Water Act. The 404(b)(1) Guidelines are the substantive criteria used in evaluating discharges of dredged or fill material into waters of the United States. The applicant would source construction fill from a local supplier.

Water Quality Certification: Section 401 of the Clean Water Act (33 U.S.C. 1341) requires applicants to obtain a water quality certification for proposed discharges into waters of the United States. A permit for the described work will not be issued until certification has been issued or is waived from the certifying state. The state’s notice for a water quality certification is attached.

Endangered Species: Section 7 of the Endangered Species Act (ESA) (16 U.S.C. 1536) requires federal agencies to consult with the National Marine Fisheries Service (NMFS) and/or U.S. Fish and Wildlife Service (USFWS) on all actions that may affect a species listed (or proposed for listing) under the ESA as threatened or endangered or that may adversely modify designated critical habitat. The Corps’ preliminary review indicates the described activity may affect an endangered or threatened species or designated critical habitat. The Corps will initiate consultation under Section 7 of the ESA. The Corps will complete the required consultation prior to finalizing a permit decision.

Essential Fish Habitat: Section 305(b)(2) of the Magnuson-Stevens Fishery Conservation and Management Act (MSA) as amended (16 U.S.C. 1855), requires Federal agencies to consult with the NMFS on all actions, or proposed actions, permitted, funded, or undertaken by the agency, that may adversely affect Essential Fish Habitat (EFH). The Corps’ preliminary review indicates the described activity would adversely affect EFH at the project location or in the vicinity. The Corps will initiate consultation under Section 305(b)(2) of the MSA. The Corps will complete the required consultation prior to finalizing a permit decision.

Historic Properties/Cultural Resources: Section 106 of the National Historic Preservation Act of 1966, as amended (54 U.S.C. 306108), requires Federal agencies to consult with the appropriate State and/or Tribal Historic Preservation Officer to take into account the effects of actions they undertake or permit on historic properties listed in or eligible for listing in the National Register of Historic Places. The Corps’ preliminary review indicates the permit area is likely to yield resources eligible for inclusion in the National Register of Historic Places. An investigation for the presence of potentially eligible historic properties is justified and would be required prior to the Corps’ final permit decision.

This notice has been provided to the Oregon State Historic Preservation Office, interested Native American Tribes, and other interested parties. If you have information pertaining to cultural resources within the permit area, please provide this information to the Corps’ project manager identified at the end of this notice to assist in a complete evaluation of potential effects.

State and Local Authorizations: The applicant has obtained approval from Wallowa County. The applicant has applied for the following additional governmental authorizations for the project: Removal-Fill Permit from the Department of State Lands (DSL) (DSL No. APP0064650).

Public Hearing: Any person may request in writing within the comment period specified in this notice that a public hearing be held to consider this application. Requests for public hearings shall state with particularity the reasons for holding a public hearing.

Evaluation: The decision whether to issue a permit will be based on an evaluation of the probable impact, including cumulative impacts, of the described activity 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 described activity, must be balanced against its reasonably foreseeable detriments. All factors, which may be relevant to the proposal will be considered including the cumulative effects thereof; among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, 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 is soliciting comments from the public; Federal, state, and local agencies and officials; Native American Tribes; and other interested parties in order to consider and evaluate the impacts of the proposed activity. Any comments received will be considered by the Corps to determine whether to issue, modify, condition or deny a permit for this proposal. To make this decision, comments are used to assess impacts on endangered species, historic properties, water quality, general environmental effects, and the other public interest factors listed above. Comments are used in the preparation of an Environmental Assessment and/or an Environmental Impact Statement pursuant to the National Environmental Policy Act. Comments are also used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.

Submitting Comments: Interested parties are invited to provide comments on the proposed project. Comments may be submitted by conventional mail or email. All comments received will be considered in determining whether authorizing the work would be contrary to the public interest. 

Either conventional mail or e-mail comments must include the Corps reference number as shown on page 1 and include the commenter’s name and address. In order to be accepted, e-mail comments must originate from the author’s e-mail account and must include on the subject line of the e-mail message the Corps reference number. All comments received will become part of the administrative record and are subject to public release under the Freedom of Information Act including any personally identifiable information such as names, phone numbers, and addresses.

Additional information about the proposed project may be obtained from the Corps Project Manager listed below. All comments, whether by conventional mail or email, must be received no later than the expiration date of this public notice to ensure consideration. Comments should be submitted to the following mailing address or email address:

        U.S. Army Corps of Engineers
        Regulatory Branch
        Ms. Danielle Erb
        P.O. Box 2946
        Portland, Oregon 97208-2946
        Telephone: (503) 808-4368

Oregon Department of Environmental Quality (DEQ)
Water Quality 401 Certification

    Notice Issued: December 28, 2023
    Written Comments Due: January 27, 2024

Corps of Engineers No: NWP-2022-494
Oregon Department of State Lands No: APP0064650    

WHO IS THE APPLICANT: Wallowa Lake Irrigation District

LOCATION OF CERTIFICATION ACTIVITY: See attached U.S. Army Corps of Engineers public notice.

WHAT IS PROPOSED: See attached U.S. Army Corps of Engineers public notice on the proposed project.

NEED FOR CERTIFICATION: Section 401 of the Federal Clean Water Act requires applicants for Federal permits or licenses to provide the Federal agency a water quality certification from the State of Oregon if the proposed activity may result in a discharge to waters of the state.

DESCRIPTION OF DISCHARGES: See attached U.S. Army Corps of Engineers public notice on the proposed project.

WHERE TO FIND DOCUMENTS: Documents and materials related to water quality issues as a result of the proposal are available for examination and copying at Oregon Department of Environmental Quality, 401 Water Quality Permit Coordinator, Northwest Region, 700 NE Multnomah Street, Suite 600, Portland, Oregon 97232. Other project materials are available by contacting the Corps per the attached public notice.

Scheduling an appointment will ensure that water quality documents are readily accessible during your visit. To schedule an appointment please call DEQ Water Quality at Northwest Region at (503) 229-5623.

Any questions on the water quality certification process may be addressed to the 401 Permit Coordinator at (503) 229-5623 or toll free within Oregon at (800) 452-4011. People with hearing impairments may call the Oregon Telecommunications Relay Service at (800) 735-2900.


Public Hearing: Oregon Administrative Rule (OAR) 340-48-0032 (2) states that “The Corps provides public notice of and opportunity to comment on the applications, including the application for certification, provided that the department (DEQ), in its discretion, may provide additional opportunity for public comment, including public hearing.” Additional Section 401 process information is available on DEQ’s webpage (

Written comments: Written comments on project elements related to water quality must be received at the Oregon Department of Environmental Quality by 5:00 p.m. on the date specified in the upper right section on page one of this notice. Comments may be submitted electronically or through standard mail.

Email –

Mail – Oregon Department of Environmental Quality, Northwest Region
    700 NE Multnomah Street, Suite #600
    Portland, Oregon 97232
    Attn: 401 Water Quality Certification Coordinator

WHAT HAPPENS NEXT: DEQ will review and consider all comments received during the public comment period. Following this review, certification of the proposal may be issued as proposed, issued with conditions, or denied. You will be notified of DEQ’s final decision if you submit comments during the comment period. Otherwise, if you wish to receive notification, please call or write DEQ at the above address. Public records can be accessed through the Your DEQ Online public records portal webpage 

ACCESSIBILITY INFORMATION: DEQ can provide documents in an alternate format or in a language other than English upon request. Call DEQ at (800) 452-4011 or email