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, including wetlands, as described below in the attached document:
APPLICANT: Lenroot Canal Company, 938 West 8200 South, Rexburg, Idaho 83440, Rick Sutton, President. (208) 709-2634.
AGENT: Eric Miller, Yellowstone Earth Science, 2202 West 8200 South, Rexburg, Idaho 83440. (208) 816-2881.
U.S. ARMY CORPS OF ENGINEERS PROJECT MANAGER: James Joyner, Idaho Falls Regulatory Office, 900 North Skyline Drive, Suite A, Idaho Falls, Idaho 83402-1718. (208) 522-1645. james.m.joyner@usace.army.mil.
PURPOSE: Maintain water delivery to water users of the Lenroot Canal Company (LCC) from the South Fork of the Snake River at LCC’s existing point of diversion. Water is delivered from the South Fork of the Snake River to the Lenroot Canal to meet decreed water rights of up to 350 cubic feet per second (cfs).
WATERWAY: South Fork of the Snake River. Work would occur in up to 3,000 feet of side-channel of the river and its adjacent wetlands.
LOCATION: The proposed project would be located on a side channel of the South Fork of the Snake River and adjacent wetlands immediately downstream of the “Twin Bridges” at South 600 E approximately 3.25 miles North of Ririe, Idaho. The location is within Section 17, Township 4 North, Range 40 East, near latitude 43.682779º N and longitude -111.771818º W, in Madison County, near Sunnydell, Idaho.
DRIVING DIRECTIONS: From Main Street in Ririe, Idaho proceed about 0.40 miles to Smith Street. At the stop sign turn right onto Smith Street. Smith Street turns into Archer Road after about 0.30 miles. Continue on Archer Road for approximately 3.2 miles to the northernmost twin bridge (Madison County side). From the north bank of the Snake River at the north “Twin Bridge” (Madison County), the general project site is located approximately 0.20 miles downstream (i.e. west) of this location.
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 permit is required for the discharge of dredged or fill material into waters of the United States, including wetlands.
WORK: Discharge of up to 1050 cubic yards of dredged river bed material (gravel and cobble) and 35 cubic yards of trees and woody debris below the ordinary high water mark (OHWM) of approximately 3000 linear feet of the South Fork of the Snake River and 0.01 acres of adjacent wetlands on an annual basis to maintain flows to the LCC headgate and canal. It is unlikely that dredging would occur along the entire 3000 linear foot project reach. The applicant indicates that in a typical year work would likely be confined to the first 250 linear feet of side channel at its upstream end.
LCC proposes to conduct periodic, as needed, excavation and re-deposition of river cobble and gravels (hereafter gravel(s)) below the OHWM of the South Fork of the Snake River and removal of downed trees and woody debris from the channel with discharge in adjacent wetlands. Gravels excavated in excess of the above volume would either be used to repair and rehabilitate a farmer’s dike at the upstream end of the project or temporarily stockpiled adjacent to the levee and removed to an upland. It is anticipated that the need to excavate gravel in excess of the 1050 cubic yards indicated above would be occasional rather than annual. The project can further be divided into discrete activities:
- Activity 1 – Periodic Reworking of Existing Gravels - Periodic dredging/reworking of gravels is proposed, as needed, following the natural accrual of sediment within the channel, to ensure storage/decreed water rights at the downstream Lenroot Point of Diversion (POD). This action may occur within the main stem of the Snake River (near the existing side channel inlet) or at any point or section between the side channel inlet and the property boundary line between the Keith Bowen Property to the south and the Lee Sutton property to the north. This represents a channel reach of approximately 750 ft (see Activity 1 figure). However, it is anticipated that most of the sediment dredging/reworking will take place near the head of the existing side channel and within several hundred feet downstream of that point. These conditions may change given the transient nature of riverbed erosion deposition in the future. Sediment dredging/reworking will consist of using a large track-hoe (or similar equipment) to rework naturally deposited gravels from the stream, as necessary, to ensure storage/decreed flow water rights at the Lenroot POD. Materials reworked from the middle portions of the stream channel would be placed near the margins of the stream channel and below the OHWM. Reasonable efforts would be made to have reworked material appear natural and inconspicuous. Although the volume of reworked gravels would vary depending on complex river dynamics, the typical volume of reworked materials for a given event is estimated to be less than 750 y3/yr. (i.e., approximately 50 ft wide x 200 ft long x 2 ft deep). The frequency of this activity will vary depending upon complex river dynamics but may occur near the beginning (March/April) or end (September/October) of a given irrigation season. Such activities may also occur in early summer following the spring freshet. High flows associated with the spring freshet often result in increased bed load which is deposited after river flows are reduced mid-season. Such mid-season actions would normally need to be completed in July/August, if required.
- Activity 2 – Periodic Removal of Trees/Woody Debris - As needed, the removal of trees and woody debris from the main channel of the Snake River and/or its side-channels to ensure adequate water delivery and to control sediment deposition and erosion. In such cases, trees and other woody debris would be removed from the channel and placed on adjoining wetlands. lt is proposed that such placement would occur between 10 ft and 50 ft landward from the OHWM of the channel in order to reduce impact to wetlands/vegetation from machinery (see Activity 2 figure). The applicant is also proposing to leave the woody material in the riparian corridor so large woody debris is not permanently removed from the system. Reasonable efforts will be made to have removed trees and woody debris appear natural and inconspicuous upon placement. Although the volume of trees and wood debris would vary depending on complex river dynamics, the typical volume of such materials for a given event is estimated to be less than 35 y3/yr. This assumes the removal of 5 dead trees per year and that these trees are 2 ft in diameter and are 60 ft in length, The frequency of this activity will vary depending upon complex river dynamics but may occur at any time prior to or during the irrigation season. Over time, the volume of such material may be large enough to prevent their placement in a "natural and inconspicuous" manner. ln this event, trees and woody debris would be temporarily placed atop the existing farmer's levee and subsequently transported off-site for upland disposal. Such staged materials would be transported off-site within six months of its placement.
- Activity 3 – Rehabilitation of Cobble/Gravel Diversion Dam - The Corps has determined that this activity is exempt from Section 404 Clean Water Act (CWA) permitting requirements as a structure appurtenant to the Lenroot Canal (an irrigation ditch) as indicated at 33 CFR 323.4(a)(3). However, the Corps is sharing information about the activity to provide transparency about potentially related actions that are not subject to CWA permitting requirements. As needed, the existing Lenroot diversion dam will be rehabilitated to ensure storage/decreed flow water rights to the Lenroot POD are met (see Plan View - Headwaters Area figure). The existing cobble/gravel diversion dam is approximately 720' long extending east of the Lenroot POD. The diversion dam varies in width from approximately 20 ft. to more than 100 ft. Typically, during high flow periods, an approximate 65 ft long section of the diversion dam is eroded which reduces available irrigation water at the Lenroot POD. The section of the diversion dam most often eroded is approximately 25 ft wide and is located approximately 580 ft. west of the Lenroot POD. As needed, the Lenroot Diversion Dam will be reconstructed/rehabilitated to its nominal geometry to ensure adequate flow to the Lenroot POD. This activity is typically completed by using a large track-hoe (or similar equipment) to dredge in-stream eroded material (generally located within 20 ft downstream from the eroded section) to rehabilitate eroded sections of the dam. Typically, the depth of water in the eroded section will be approximately 2 ft. The dam top elevation is approximately 3 ft above the OHWM. Consequently, the volume of in-steam material necessary to rehabilitate the eroded section will typically be less than 300 y3/yr. (i.e., 5 ft high x 25 ft wide x 65 ft long). Generally, this rehabilitation is only required at the location described above (i.e. approximately 580 ft. west of the Lenroot POD). However, such erosion could occur at any location along the approximate 720 ft long diversion dam structure.
- Activity 4 – Rehabilitation of Existing Farmer’s Levee - lf the volume of required sediment dredging/reworking (i.e., Activity 1) cannot be completed below the OHWM, additional sediment dredging/removal would be required to ensure storage/decreed flow water rights at the downstream Lenroot POD are met. This action may occur within the main stem of the Snake River (near the existing side channel inlet) or at any point or section between the side channel inlet and the property boundary line between the Keith Bowen Property to the south and the Lee Sutton property to the north. This represents a channel reach of approximately 750 ft (see Activity 4 figure). However, it is anticipated most sediment dredging/removal will take place near the head of the existing side channel and within several hundred feet downstream of that point. This may change given the transient nature of riverbed erosion deposition in the future. Sediment dredging/removal will consist of using a large track-hoe (or similar equipment) to remove gravels from the stream. Dredged materials, in excess of that which could be reasonably reworked below the OHWM (in Activity 1), would be placed on eroded sections of the existing "farmer's levee" in order to rehabilitate and maintain the function of the existing farmer's levee (primarily erosion control). ln such cases, dredge material will only be placed to the extent that it roughly corresponds to the original (circa 1959) levee geometry (see Plan View - Levee Repair Area figure) and limited to the elevation of the current levee top (approximately 4,948 ft above mean sea level (amsl)).
- Activity 5 – Dredging and Removal of Cobble/Gravel - On rare occasions, the volume of necessary sediment dredging/reworking (i.e., Activity 1) and/or dredging/levee repair (i.e., Activity 4) may be large enough to require some volume of dredging/off-site removal. ln such instances, excess dredge material will be temporarily staged within the footprint of the existing farmer's levee (see Plan View - Levee Repair Area figure) and subsequently transported off-site or staged for future levee repairs. ln these rare cases, although the staged dredge material with be contained within the lateral footprint of the farmer's levee (to avoid impacted nearby wetlands), its top elevation may be temporarily higher than the historic levee top elevation (approximately 4,948 ft amsl). Such staged material would be used in subsequent farmer's levee repair maintenance or transported off-site within six months of its placement. Although the volume of excavated gravels would vary depending on complex river dynamics, the typical volume of excavated materials for a given event is estimated to be less than 50 y3/yr.
It should be noted that Activities 1, 4 and 5 are not additive but generally represent a preferred order of dredge material discharge by the applicant (i.e., Activity 1 preferred before Activity 4; Activity 4 preferred before Activity 5) to maintain irrigation flows.
For example, if the volume of gravels dredged per year is approximately 1050 y3 and all that material could be re-worked/discharged below the OHWM then only Activity 1 would be performed that year/event.
If 1050 y3 were dredged and only 750 y3 could be reasonably discharged below the OHWM and all the remaining material could be used to repair/maintain the farmer’s dike, then both Activity 1 and Activity 4 would be performed that year.
ADDITIONAL INFORMATION: Dredging/excavation of gravels would also likely occur annually, as needed, near the POD. The Corps has determined that, in this particular case, dredging/excavation within 250 feet of the POD is exempt from Section 404 Clean Water Act permitting requirements as indicated at 33 CFR 323.4(a)(3). The Corps is sharing information about the activity to provide transparency about potentially related actions that are not subject to CWA permitting requirements.
CONSTRUCTION PERIOD: 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 2021. A permit duration of 10 years is requested.
PROPOSED MITIGATION: The applicant proposes the following mitigation measures to avoid, minimize, and compensate for impacts to Waters of the United States from activities involving discharges of dredged or fill material.
- LCC would perform excavation and re-working of gravels during low/no flow conditions to minimize stream turbidity.
- Excavation and re-working of gravels will be performed with heavy equipment working atop the riverbank rather than in-stream when feasible.
- Mobilization of large equipment used for excavation and re-working of gravels would be limited to established roadways where possible. Where movement or placement of large equipment cannot be reasonably restricted to roadways, efforts will be made to minimize disturbance to vegetated areas.
- When possible, during excavation and re-working of gravels the Lenroot POD will be opened to allow for turbid water, if observed, to be diverted to the Lenroot POD.
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 provide them notice of their preliminary 401 Certification decision. Comments concerning Water Quality Certification for this project should be mailed to:
Mr. Troy Saffle
Idaho Department of Environmental Quality
Idaho Falls Regional Office
900 North Skyline Drive, Suite B
Idaho Falls, Idaho 83402
AQUATIC RESOURCE DESCRIPTION: The South Fork of the Snake River at this location consists of a braided network of channels and is a nationally renowned trout fishery. Flows in this section of the river frequently move from one channel to another, leaving once dominant flow paths as nearly de-watered side channels. The floodplain of the river in this location is much wider than in the upstream canyon section. While a large cottonwood gallery persists along much of the riparian corridor there is also substantial agricultural development in and near the floodplain of the river that is fed by a network of irrigation ditches and canals.
ANTICIPATED IMPACTS ON AQUATIC ENVIRONMENT: The project, as proposed, would impact the South Fork of the Snake River through excavation and redeposition of dredged materials. With regard to Activity 1, during a normal, non-flood/non-drought year, the anticipated impacts will be very minimal. Excavation of gravels at the upstream end of the side channel may occur to improve flows to the POD. Typical work would involve up to 750 feet of channel excavation with concurrent re-deposition of approximately 1050 cubic yards of dredged materials below the OHWM of the river along the channel margins. However, at times it may be necessary to dredge anywhere from the mouth of the side channel to the POD (approximately 3,000 feet of channel). Activity 2 could result in up to 600 square feet of fill in adjacent riparian wetlands associated with the disposal of trees and woody debris removed from the side channel. Additionally, there may be minor or temporary impacts to the river and adjacent wetlands associated with the other activities, namely repairing and rehabilitating the farmer’s dike and temporarily stockpiling excavated gravels and woody debris prior to removal to uplands.
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 through its authorities under Section 401 of the Clean Water Act with respect to issuance of Water Quality Certification for the project.
CULTURAL RESOURCES: Coordination is currently being conducted with the office of the Idaho State Historic Preservation Officer to determine if this activity will affect a site that is listed on the National Register of Historic Places, or a site 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, 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 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: The project is within the known or historic range of Yellow-billed Cuckoo (Threatened) and Ute Ladie’s-tresses (Threatened). Coordination is 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).
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 and there is no designated EFH in 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 activity. 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 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.
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
James M. Joyner
Idaho Falls Regulatory Office
900 North Skyline Drive, Suite A
Idaho Falls, Idaho 83402-1700
james.m.joyner@usace.army.mil
Comments should be received no later than the comment due date of November 21, 2020, as indicated on this notice, to receive consideration.