Public Notices

Listed below are the current Public Notices published by the Walla Walla District for proposed projects within the state of Idaho. The Public Notices are sorted by Effective Date and are provided in PDF format. You must have Adobe Acrobat Reader installed on your PC to view these files. 

Viewing Public Notices. To view a Public Notice, left-click on the Permit Application Number (highlighted in blue). To download the file to your PC, right-click on the Permit Application Number, then select "Save Target As" from the menu.

How to Submit Comments. To submit comments via email, cut and paste the email address of the respective Project Manager's from the table below into an email and in the subject line of your email enter: Public Notice Comments for (referencing the specific project).  To submit comments in writing, send them to the respective Project Manager at the U.S. Army Corps of Engineers, Walla Walla District Regulatory Division, 720 E. Park Blvd., Suite 245, Boise, ID 83712. All comments should include the permit application number and project name, your name, address, and phone number.

NWW-2017-00612-I01: Blaine County, Hiawatha Canal Company River Work

Published March 12, 2020
Expiration date: 4/12/2020

Interested parties are hereby notified that the Walla Walla District has received an application for a Department of the Army permit for certain work in Waters of the United States, as described below in the attached documents:

  • NWW-2017-622_PN_Drawings_7_Pages.pdf

APPLICANT:  Hiawatha Canal Company, PO Box 1604, Hailey, Idaho 83333, Jim Phillips, Chairman.  208-788-3496.

U.S. ARMY CORPS OF ENGINEERS PROJECT MANAGER:  Robert Brochu, Idaho Falls Regulatory Office, 900 North Skyline Drive, Suite A, Idaho Falls, Idaho, 83402-1718.  208-522-1645.

PURPOSE:  Maintain water delivery to water users of the Hiawatha Canal Company (HCC) and control flows from the Big Wood River to the Hiawatha Canal headworks.   Water is delivered from the Big Wood River to the Hiawatha Canal to meet decreed water rights of approximately 68 cubic feet per second (cfs).

WATERWAY:  Big Wood River and a side-channel locally known as the By-Pass Canal/Channel (BPC).  The side channel is approximately 1800 feet long from origin to reintegration into the Big Wood River.

LOCATION:  The proposed project is located on the east bank of the Big Wood River adjacent to the Starweather Subdivision approximately 4.5 miles north of Hailey, Idaho. Access to the BPC diversion structures (hearafter headworks) on the Big Wood River is through a dirt road/right-of-way in the subdivision.

The location is within the SE ¼ of the NE ¼ of Section 19, Township 3 North, Range 18 East, Boise Meridian, near Latidude 43°34’52” North and Longitude -114°20’43”, Blaine County, Idaho.  A location map is provided on Sheet 1 of 7 in the drawings.

DRIVING DIRECTIONS:  From Hailey drive north on State Highway 75 for 4.5 miles.  Turn west onto Starweather Drive.  Continue for 0.25 miles and turn left (southerly) onto Canvas Back Lane.  Approximately 75 yards on the southwest is a gated, unnamed dirt road.  The canal headwork is approximately 300 yards down the road.  Permission to enter the drive must be obtained from the applicant prior to entry.

AUTHORITY:  This permit will be issued or denied under the authority of Section 404 of the Clean Water Act (33 U.S.C. 1344).  A Department of the Army (DA) permit is required for the discharge of dredged or fill material into waters of the United States, including wetlands. The terms dredge and excavate are used herein synonymously. The term re-deposition used herein is the discharge of locally excavated material.

WORK:  HCC proposes to conduct periodic excavation and re-deposition of river cobbles and gravels (hereafter gravels) below the ordinary high water mark of the Big Wood River, including the BPC, to maintain and control flows to the Hiawatha Canal headworks.  The headworks include a channel-spanning concrete dam or check structure and adjacent canal headgate.

Frequency of excavation and re-deposition operations will vary but based on past operations, HCC does not anticipate substantial excavation and re-deposition actions to occur every year.  Rather, the full scale of actions described below are anticipated to occur on 2 to 5 year intervals.  Annually, HCC anticipates only minor excavation operations near the headworks.  Please note that limited excavation and re-deposition at the headworks may not require a DA permit.

HCC anticipates three situations when work would occur in the river and require a DA permit:

Situation 1) Low Flow River Condition (Sheets 2 and 5 of 7). In this situation, Big Wood River flow is not reaching the headworks in sufficient volume to meet the decreed water rights.  HCC would excavate a channel through the bed of Big Wood River and BPC to provide flow to the headworks.  The excavated channel would be dimensioned to maintain a 200 cfs flow to the headworks.  Depending on river levels, the excavated channel would be between 10 and 30 feet wide and one to two feet deep below the active water level.  Under a typical excavation situation, the volume is anticipated to vary from 10 to 200 cubic yards.  Channel excavation will normally be limited to 100 to 200 feet in length, upstream of the headworks, and may not be contiguous.    Approximately 0.1 acres BPC would be excavated and the re-deposition of excavatied materials filling upwards of 0.2 acres of BPC below the ordinary high water mark of the Big Wood River. 

Rare scenarios would occur during drought years or extreme high flow events.  High flow events are thought to occur approximately 1 in 10 years.  In these events, the BPC and a portion of the Big Wood River may require excavation upstream of the headworks and impact up to 730 feet of channel.  In total, approximately 1600 cubic yards of gravel may be excavated, impacting up to 0.5 acres of the Big Wood River and BPC.  Excavated material will be re-deposited onto un-vegetated banks of the BPC below the ordinary high water mark.  Initially and typically, gravels will be re-deposited upstream of the headworks, no farther than the upstream confluence of the BPC and main channel Big Wood River.  Again, the upstream portion of the BPC would be maintained to convey at least 200 cfs to the headworks.  Re-deposition may occur downstream of the headworks if re-deposition upstream would restrict flow to the headworks to less than 200 cfs.  Sheet 6 of 7 depicts a conceptual cross section of the proposed re-deposition. Following a drought year(s), gravel located at the origin of the BPC and Big Wood River may need to be redistributed to establish the minimum 200 cfs to the headworks.  In these extreme scenarios, HCC anticipates that re-deposition activities will result in approximately 0.3 to 0.5 acres of impacts to the BPC. 

Situation 2) High River Flows (Sheet 3 of 7). This situation would occur in anticipation of high river flows.  Work would occur before high water and mostly in the dry.  It would involve excavation of river gravel and re-deposition of gravel to establish a gravel bar to limit Big Wood River flow into the BPC.  A snow pack in excess of 120% of the 30-year average for the Big Wood River will be the proposed trigger for such construction.  The constructed gravel bar would be approximately 200 feet long and 20 to 30 feet wide, constructed to a height up to 1 foot below the ordinary high water elevation.  Up to 12,000 square feet of river bed excavation may be required to construct the gravel bar, which would occupy approximately 6,000 square feet of river bed. The establishment of a flow limiting gravel bar would not impede the entire BPC.

Situation 3) Snagging & Removal of Trees, Woody Debris (Sheet 4 and 7 of 7).  The third situation is the snagging and removal of trees and woody debris from the Big Wood River and BPC.  This occurs after higher flow events in the river and might occur coincident with Situation 2.  Periodically, large cottonwood trees fall into the river as a result of natural riverine erosion processes.  These trees, when grounded on the river bed, can redirect river flow and alter gravel movement in the river.  HCC proposes to identify trees or woody debris that have already obstructed or are likely to obstruct river flow and drag these trees or woody debris into a pile above the ordinary high water mark of the river where they will be allowed to dry.  The piles may result in temporary discharges in scrub wetlands along the Big Wood River and BPC along the fringe of the existing forested wetland area depicted on Sheets 4 of 7 and 7 of 7.  When conditions are conducive to safe burning (normally winter), the piles would be relocated to un-vegetated gravel bars to be burned (Sheet 7 of 7).   It is estimated that up to 0.15 acres of scrub wetlands may be temporarily impacted by the woody debris piles.

ADDITIONAL INFORMATION:  HCC has operated the Hiawatha Canal for over 100 years.  The Hiawatha Canal was constructed in 1883.  HCC has historically needed to excavate and re-deposit river gravel and cobble in the project area periodically on an as-needed basis in response to high flow events and normal cobble and gravel aggradation.

During the 2017 high river flows, trees and gravel were deposited in the Big Wood River downstream of the origin of the BPC, resulting in channel obstructions which prompted greater than normal flows into the BPC.  The HCC headworks were substantially damaged and HCC had to undertake repairs to the check structure, headgate and riverbanks to prevent failure of the headgate and flooding inland along the Hiawatha Canal, which would have threatened downstream homes, including the City of Hailey.  This situation is what led the applicant to request authorization for the aforementioned scenarios, to plan for future needs as best as possible. 

CONSTRUCTION PERIOD:  The applicant proposes to start construction upon receipt of all federal, state, and local permits.  It is anticipated that work would begin before high water in 2020.  A permit duration of 10 years is requested.

PROPOSED MITIGATION:  The applicant proposes the following mitigation measures to avoid, minimize, for impacts to Waters of the United States from activities involving discharges of dredged or fill material.

  • HCC would perform excavation of river cobbles and gravels during low flow conditions and in the dry, whenever possible.
  • During excavation and re-deposition activities, HCC will open the canal headgate and divert turbid water, if observed, into the Hiawatha Canal.
  • Burning of trees and woody debris removed from the Big Wood River and/or BPC would be performed in compliance with state and local requirements.  Burning would not occur in the shrub or forested area but instead would occur on an un-vegetated gravel bar.
  • To protect adjacent wetlands, gravel and cobble re-deposited adjacent to the BPC would be outside of any vegetated areas.
  • To addess aesthetics, gravel and cobble re-deposited adjacent to the BPC would be smoothed and graded to appear naturally deposited.
  • To address floodplain management, re-deposited gravel would not restrict overland flows during high water events.  The re-deposited gravel and cobble will not have the appearance of or function as a berm or levee.

WATER QUALITY CERTIFICATION:  This notice will also serve as a Public Notice that the Idaho Department of Environmental Quality (IDEQ) is evaluating whether to certify that the discharge of dredge and/or fill material proposed for this project will not violate existing water quality standards.  A Department of the Army permit will not be issued until water quality certification has been issued or waived by the IDEQ as required by Section 401 of the Clean Water Act.  If water quality certification is not issued, waived or denied within sixty (60) days of this public notice date, and an extension of this period is not requested by and granted to the IDEQ certification will be considered waived.  Additionally, within thirty (30) days of this Public Notice, any person may provide written comments to IDEQ and request in writing that IDEQ provides them notice of their preliminary 401 Certification decision. Comments concerning Water Quality Certification for this project should be mailed to:

Ms. Sue Switzer

Idaho Department of Environmental Quality

Twin Falls Regional Office

650 Addison Avenue West, Suite 110

Twin Falls, Idaho  83301

AQUATIC RESOURCE DESCRIPTION:  According to the “Final Geomorphic Asessment Report, Big Wood River, Blaine County, Idaho” prepared by Biota Research and Consulting for Trout Unlimited, dated February 1, 2016, the reach of the Big Wood River downstream of the East Fork Big Wood River and upstream of Deer Creek is entrenched with high to moderalte width/depth ratio and has low sinuosity.  The bank erosion rate is estimated to be near 0.0539 tons/year/foot.  The report determined that this reach has excess sediment deposition. 

This reach of the Big Wood River supports extensive cottonwood forests along its riparian margin.  Based on aerial imagery, the cottonwood forest along the Big Wood River varies in width from 2,200 feet to 1,000 feet between the East Fork and Deer Creek.  In this reach several residential subdivisions exist within the historic floodplains of the river, primarily on the east banks of the river. 

The Big Wood River is constrained geologically by the mountains to the west and human development along the river.  Approximately 1,600 feet upstream of the BPC, a private road bridge with armored abutments at the river’s edge restricts lateral migration of the channel.  A mountain ridge projects from the west easterly downstream of the HCC headworks, pinching the river between the mountain and the Zinc Spur subdivision.

ANTICIPATED IMPACTS ON AQUATIC ENVIRONMENT:  The project, as proposed, would impact the Big Wood River and the BPC through excavation and re-deposition of dredged materials.  In Situation 1, during a normal, non-flood/non-drought year, the anticipated impacts will be very minimal.  Excavation of gravels at the headworks may occur to open the headgate.  Work would occur in the dry or at low flow periods and upwards of 200 feet of channel may be excavated with concurrent re-deposition of approximately 10 to 200 cubic yards of dredged materials adjacent to the resulting channel.  Re-deposited dredged material would be graded into the existing bankline.  Herein approximately 0.1 acres BPC would be excavated with upwards of 0.2 acres of BPC filled below the ordinary high water mark of the Big Wood River.  In the case of flood repair or extreme drought, the upstream portion of the BPC would be excavated upwards of 730 linear feet by 30 feet wide resulting in excavation of approximately 0.50 acres of the bed of the BPC.  The estimated 1,600 cubic yards of dredged material would then be redeposited below the ordinary high water mark of the Big Wood River along the banks of the BPC with a footprint of approximately 0.5 acres.

In the 2nd Situation, in anticipation of high spring flows, the HCC would construct a flow limiting gravel bar at the mouth of the BPC. The constructed gravel bar would be approximately 200 feet long and 20 to 30 feet wide, constructed to a height up to 1 foot below the ordinary high water elevation.  Approximately 450 cubic yards of gravel would be excavated from approximately 12,000 square feet of Big Wood River, and BPC bed excavation may be required to construct the gravel bar, which would occupy approximately 6,000 square feet of river bed.

The 3rd Sitiuation, to snag and remove trees and woody material from the Big Wood River and BPC may occur annually to the extent of 6 to 10 trees, or non-routinely after high flows, to the extent of 20 plus trees.  It is estimated that up to 0.15 acres of scrub wetland may be temporarily impacted by woody debris storage.  Long term elimination of wetlands is not anticipated.

OTHER AUTHORIZATIONS:  Approvals for the proposed activities may be required by the Idaho Department of Water Resources.  As stated above, approval is required by the Idaho Department of Environmental Quality.

CULTURAL RESOURCES:  Coordination is currently being conducted with the office of the Idaho State Historic Preservation Office to determine if this activity will affect sites: one that is listed on the National Register of Historic Places, and one that may be eligible for listing on the Register.  We are also coordinating with the appropriate Tribal entity or the Tribal Historic Preservation Offices for the Shoshone-Bannock Tribes of Fort Hall and the Shoshone-Paiute Tribes of Duck Valley, to determine if there are any tribal historic or cultural interests within the project area.

TRIBAL TREATY RIGHTS and INTERESTS:  Federal agencies acknowledge the federal trust responsibility arising from treaties, statues, executive orders, and the historical relations between the United States and American Indian Tribes.  The federal government has a unique trust relationship with federally recognized American Indian Tribes, including the Shoshone-Bannock and Shoshone-Paiute Tribes.  The Corps has a responsibility and obligation to consider and consult on potential effects to Tribal rights, uses and interests.  The Corps further recognizes there may be a need for additional and on-going consultation. 

ENDANGERED SPECIES:  No listed threatened or endangered species or designated critical habitats are known to exist in the project area.  Coordination was currently being conducted with the U.S. Fish and Wildlife Service (USFWS) to determine if the activity will have any effect on species designated as endangered or threatened under the Endangered Species Act, or their critical habitat, under the Endangered Species Act of 1973 (87 Stat. 844; 16 U.S.C. 1531 et. seq.).

ESSENTIAL FISH HABITAT:  The Magnuson-Stevens Fishery Conservation and Management Act, as amended by the Sustainable Fisheries Act of 1996, requires all Federal agencies to consult with the National Marine Fisheries Service on all actions or proposed actions, permitted, funded or undertaken by the agency that may adversely affect Essential Fish Habitat (EFH).  No EFH species are known to use the project area.  Preliminarily, we have determined the described activity would have no effect on EFH.

ENVIRONMENTAL IMPACT STATEMENT:  Preliminary review indicates the proposed activities will not require preparation of an Environmental Impact Statement. Comments provided will be considered in preparation of an Environmental Assessment.

EVALUATION:  The decision whether to issue a permit will be based on an evaluation of the probable impact, including cumulative impacts, of the proposed activity on the public interest.  This 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, 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.  In addition, our evaluation will include application of the EPA Guidelines (40 CFR 230) as required by Section 404(b)(1) of the Clean Water Act.

CONSIDERATION OF PUBLIC COMMENTS:  The Corps of Engineers is soliciting comments from the general public; Federal, State, and local agencies and officials, Tribal entities and other interested parties in order to consider and evaluate the impacts of this proposed project.  Any comments received will be considered by the Corps of Engineers 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 received in response to this Public Notice will be used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.

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 proposed activity.  Requests for a public hearing shall state specific reasons for holding a public hearing. A request may be denied if substantive reasons for holding a hearing are not provided or if there is otherwise no valid interest to be served.

COMMENT & REVIEW PERIOD:  Interested parties are invited to provide comments on the proposed activity, which will become a part of the record and will be considered in the final decision. 

Please mail all comments to:

U.S. Army Corps of Engineers

Walla Walla District

Robert A. Brochu

Idaho Falls Regulatory Office

900 N Skyline Drive, Suite A

Idaho Falls, Idaho  83402-1700

Comments should be received no later than the comment due date of April 12, 2020, as indicated on this notice, to receive consideration.                                                                 


                                                                  Kelly J. Urbanek

                                                                  Chief, Regulatory Division

                                                                  Walla Walla District



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