404_Stoddard_Road_Improvements-Signed_Verification_Letter-8-7-26.pdf

DEPARTMENT OF THE ARMY

U.S. ARMY CORPS OF ENGINEERS

BOISE REGULATORY OFFICE

720 EAST PARK BOULEVARD, SUITE 245

BOISE, IDAHO 83712-7757

August 7, 2026

WALLA WALLA DISTRICT

REGULATORY DIVISION

SUBJECT: NWW-2026-0000134, Ada County Highway District, Stoddard Road Widening Project, Ridenbaugh Canal and Hardin Drain

Logan Hansen Ada County Highway District 5800 N. Meeker Avenue Boise, ID 83713

Dear Mr. Hansen:

We have determined that your proposed project is authorized in accordance with Department of the Army (DA) Nationwide Permit (NWP) No. 14: Linear Transportation Projects. Project activities are situated at two distinct sites along Stoddard Road, within the proposed improvement zone between Victory Road and Overland Road, within Section 24 of Township 3 North, Range 1 West, at the coordinates listed in Table 1, in Meridian, Ada County, Idaho. Please refer to File Number NWW-2026-00134 in all future correspondence with our office regarding this project.

Table 1. NWP Site Number and Location.

NWP 14

Site No.

Impacted Aquatic Resources

Single and Complete Project Center Point Latitude Longitude

1 Ridenbaugh Canal 43.5774° -116.4037° 2 Hardin Drain 43.5870° -116.4036°

Project activities include the discharge of approximately 156 cubic yards of fill material below the ordinary high water mark (OHWM) of Ridenbaugh Canal and approximately 67 cubic yards of fill material below the OHWM of Hardin Drain, which may be considered waters of the United States. The purpose of the project is to widen Stoddard Road Bridge (#2085) at its crossing of the Ridenbaugh Canal and pipe a section of the Hardin Drain along Stoddard Road, to accommodate the widening of the entire road segment between Victory Road and Overland Road and install pedestrian utilities.

These improvements will help accommodate for future traffic volumes and improve safety features in the area due to the ongoing development in Meridian. Project activities proposed at each site include:

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Site 1 - Ridenbaugh Canal

• The implementation of best management practices (BMPs) and a dewatering structure and bypass piping;

• The removal of the existing concrete culvert headwalls, wingwalls, and footings;

• The excavation of approximately 101 cubic yards of fill and 20 cubic yards of concrete streambed liner;

• The extension of the existing 16.8 foot wide open-bottom culvert by 7.7 feet on the east side and 17.7 feet on the west side with cast-in-place concrete culverts and wingwalls that will match the grade of the existing culvert floor and streambed liner outside of the extended structures;

• The placement of crushed aggregate rock below the culvert extensions and wingwall footings and;

• The removal of temporary BMPs and dewatering structures and rehabilitate and reseed temporarily impacted areas.

Work will result in the discharge of approximately 156 cubic yards of fill material, resulting in permanent impacts to approximately 0.017 acres of streambed along 27 linear feet of Ridenbaugh Canal. Work would also result in approximately 0.004 acres of temporary impacts of streambed from the installation of the dewatering structures.

Site 2 - Hardin Drain

• The implementation of best management practices (BMPs);

• The removal of the two existing 30-inch diameter pipes measuring 17 feet and

90 feet in length;

• The installation of a new 36-inch diameter by 160 feet long storm drain pipe that will tie into existing irrigation structures;

• The filling of the piped area with approximately 67 cubic yards of compacting backfill and;

• The removal of temporary BMPs and rehabilitate and reseed temporarily impacted areas.

Work will result in the discharge of approximately 67 cubic yards of fill material, resulting in permanent impacts to approximately 0.01 acres of streambed along 107 linear feet of Hardin Drain.

In total, the proposed project will permanently impact approximately 0.027 acres of streambed.

Proposed activities occurring in the uplands (above the OHWM), are activities not regulated by the Corps.

All work shall be done in accordance with the enclosed drawings, titled:

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• ACHD, Culvert Widening, Ridenbaugh Canal, Sheet 1 of 3, dated March 30, 2026 by the Corps

• ACHD, Culvert Widening, Ridenbaugh Canal, Sheet 2 of 3, dated March 30, 2026 by the Corps

• ACHD, Pipe Open Ditch, Hardin Drain, Sheet 3 of 3, dated March 30, 2026 by the Corps

DA permit authorization is necessary because your project may involve the discharge of fill material into waters of the U.S. This authorization is outlined in Section 404 of the Clean Water Act (33 U.S.C. 1344).

You must comply with all general, regional, and special conditions, for this verification letter to remain valid and to avoid possible enforcement actions. The general and regional permit conditions for NWP No. 14: Linear Transportation Projects are attached and also available online1. In response to our coordination with external agencies and tribes, the following general condition is being reiterated in this letter:

21. Discovery of Previously Unknown Remains and Artifacts: Permittees that discover any previously unknown historic, cultural or archeological remains and artifacts while accomplishing the activity authorized by an NWP, they must immediately notify the district engineer of what they have found, and to the maximum extent practicable, avoid construction activities that may affect the remains and artifacts until the required coordination has been completed. The district engineer will initiate the Federal, Tribal, and state coordination required to determine if the items or remains warrant a recovery effort or if the site is eligible for listing in the National Register of Historic Places.

In addition, you must also comply with the special conditions listed below.

1. Your permit has been issued while Monarch Butterfly is proposed as “threatened” under the Endangered Species Act (ESA). Should the Monarch Butterfly be listed under the ESA prior to the completion of the project please contact the U.S. Army Corps of Engineers for an evaluation of effect determination.

2. Your permit has been issued while Suckley’s Cuckoo Bumble Bee is proposed as “endangered” under the Endangered Species Act (ESA). Should the Suckley’s Cuckoo Bumble Bee be listed under the ESA prior to the completion of the project please contact the U.S. Army Corps of Engineers for an evaluation of effect determination.

3. The permittee is responsible for all work done by any contractor or agent. The permittee shall ensure any contractor or agent who performs the work is informed

1 http://www.nww.usace.army.mil/Business-With-Us/Regulatory-Division/Nationwide-Permits/ http://www.nww.usace.army.mil/Business-With-Us/Regulatory-Division/Nationwide-Permits/

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You must also comply with the conditions detailed in the attached Section 401 Water Quality Certification (WQC) issued by the Idaho Department of Environmental Quality (IDEQ) on December 16, 2025. If you have any questions regarding the conditions set forth in the WQC, please contact IDEQ directly at 208-373-0550, Boise Regional Office.

Nationwide Permit General Condition 30 (Compliance Certification) requires that every permittee who has received NWP verification must submit a signed certification regarding the completed work and any required mitigation. This Compliance Certification form is enclosed for your convenience and must be completed and returned to us within 30 days of your project’s completion.

This letter of authorization does not convey any property rights, or any exclusive privileges and does not authorize any injury to property or excuse you from compliance with other Federal, State, or local statutes, ordinances, regulations, or requirements which may affect this work.

This verification is valid until March 15, 2031, unless the NWP is modified, suspended or revoked. If your project, as permitted under this NWP verification, is modified in any way you must contact our office prior to commencing any work activities. In the event that you have not completed construction of your project by March 15, 2031, please contact us at least 60-days prior to this date. A new application and verification may be required.

We actively use feedback to improve our delivery and provide you with the best possible service. If you would like to provide feedback, please take our online survey2.

If you have questions or if you would like a paper copy of the survey, please contact the Walla Walla District Regulatory. For more information about the Walla Walla District Regulatory program, you can visit us online3.

If you have any questions or need additional information about this permit authorization, you can contact me by phone at (208) 433-4478, by mail at the address in the letterhead, or email at nicole.e.deinarowicz@usace.army.mil. For informational purposes, a copy of this letter has been sent to: Idaho Department of Environmental Quality and Idaho Department of Water Resources.

2 https://regulatory.ops.usace.army.mil/customer-service-survey/ 3 http://www.nww.usace.army.mil/Business-With-Us/Regulatory-Division/ mailto:nicole.e.deinarowicz@usace.army.mil https://regulatory.ops.usace.army.mil/customer-service-survey/ http://www.nww.usace.army.mil/Business-With-Us/Regulatory-Division/

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Sincerely, Nicole Deinarowicz Project Manager, Regulatory Division

Encls Transfer of Nationwide Permit Form Compliance Certification Nationwide Permit 14 Terms and Conditions General Water Quality Certification Drawings (3 Sheets)

TRANSFER OF NATIONWIDE PERMIT

When the structures or work authorized by this Nationwide Permit, NWW-2026- 0000134, Ada County Highway District, Stoddard Road Widening Project, Ridenbaugh Canal and Hardin Drain, are still in existence at the time the property is transferred. The terms and conditions of this Nationwide Permit, including any special conditions, will continue to be binding on the new owner(s) of the property. To validate the transfer of this Nationwide Permit, the associated liabilities and compliance with the terms and conditions the transferee must sign and date below.

Name of New Owner:

Street Address:

Mailing Address:

City, State, Zip:

Phone Number:

Signature of TRANSFEREE DATE