Nationwide_Permit_14.pdf

DEPARTMENT OF THE ARMY

U.S. ARMY CORPS OF ENGINEERS

BOISE REGULATORY OFFICE

720 EAST PARK BOULEVARD, SUITE 245

BOISE, IDAHO 83712-7757

September 1, 2026

WALLA WALLA DISTRICT

REGULATORY DIVISION

SUBJECT: NWW-2026-00210, Ada County Highway District, Cloverdale Road Expansion Project, Eightmile Creek

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

Dear Mr. Hansen:

We have determined that your proposed project to expand Cloverdale Road is authorized in accordance with Department of the Army (DA) Nationwide Permit (NWP) No. 14: Linear Transportation Projects. This project is situated along Cloverdale Road between Victory Road and Overland Road, within Township 3 North, Range 1 East, Section 21 near coordinates 43.5829681°N latitude, -116.3343846°W longitude, in Boise, Ada County, Idaho. Please refer to File Number NWW-2026-00210 in all future correspondence with our office regarding this project.

Project activities include the discharge of approximately 227 cubic yards of fill material below the ordinary high water mark (OHWM) of Eightmile Creek, which may be considered waters of the United States. The purpose of the project is to widen Cloverdale Road from two lanes to five lanes to accommodate increased traffic due to new development and population growth. Project activities include:

• The implementation of best management practices (BMPs);

• The removal of the existing 48-inch diameter by 57 feet long corrugated metal pipe (CMP) and backfilling approximately 166 cubic yards of fill material;

• The excavation of approximately 152 cubic yards just north of the existing CMP for the placement of the new 48-inch diameter by 95 feet long reinforced concrete pipe (RCP);

• The excavation of approximately 102 cubic yards for the cast-in-place concrete headwall and the backfilling of approximately 197 cubic yards of backfill for the RCP and headwall;

• The placement of approximately 13 cubic yards of bank and scour protection consisting of a geotextile fabric below 1-foot D50 riprap along the canal bottom at the eastern mouth of the culvert and headwall opening;

- 2 -

• The excavation of approximately 8 cubic yards for the placement of a new cast-in-place irrigation structure on the west side of the road and;

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

Work will result in the discharge of approximately 227 cubic yards of fill material, resulting in permanent impacts to approximately 0.034 acres of streambed along 133 linear feet of Eightmile Creek.

All work shall be done in accordance with the enclosed drawing, titled Eight Mile Creek, Sheet 2, dated June 2, 2026 (dated 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

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/

- 3 -

“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 of and follows all the terms and conditions of this authorization.

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.

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

- 4 -

If you have any questions or need additional information about this 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.

Sincerely, Nicole Deinarowicz

Environmental Resource Specialist Regulatory Division

Encls Transfer of Nationwide Permit Form Compliance Certification Nationwide Permit 14 Terms and Conditions General Water Quality Certification Drawings titled: Eight Mile Creek, Sheet 2, dated June 2, 2026 (dated by the Corps) mailto:nicole.e.deinarowicz@usace.army.mil

TRANSFER OF NATIONWIDE PERMIT

When the structures or work authorized by this Nationwide Permit, NWW-2026-00210, Ada County Highway District, Cloverdale Road Expansion Project, Eightmile Creek, 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