DEQ seeks comment on draft 401 water quality certification for ​Topaz Ranch West Subdivision number two

Accepting comments from February 18, 2025, through March 11, 2025.

BOISE – The Idaho Department of Environmental Quality (DEQ) is seeking comment on a draft water quality certification for the Topaz Ranch West Subdivision number two project.

This project proposes backfilling approximately 580 feet and 330 feet of two abandoned irrigation ditches along both sides of the Horton Lateral and place in 1,500 cubic feet of material, impacting 0.06 acres within the project boundary. To maintain drainage for upstream users, an overflow ditch will be tiled, discharging flow above the ordinary high-water mark of the Solomon Drain. This tiling will require approximately 1,200 feet of 12-inch PVC piping, impacting 0.03 acres. A pipe culvert will be constructed across the Horton Lateral for a road crossing, involving about 132 cubic feet of concrete below the ordinary high-water mark, impacting 0.008 acres, with a 30-inch concrete pipe channeling water through the culvert.

Based upon review of the federal ​permit​ application, readily available water quality related materials, and certification request in accordance with 40 C.F.R. §§ 121.5 (b) and (c) and 121.7 (c), DEQ, certifies that if the permittee complies with the terms and conditions imposed by the federal ​permit​ and the conditions set forth in this water quality certification, then it is reasonable for DEQ to conclude that the activity will comply with water quality requirements, including applicable requirements of the Clean Water Act §§ 301, 302, 303, 306, and 307, Idaho’s “Water Quality Standards” (IDAPA 58.01.02), and other appropriate water quality requirements of state law.  

The draft certification is available for review on DEQ’s Public Comment Opportunities web page. Written comments will be accepted through February 18, 2025, at 5 p.m. Mountain Time. Submit comments electronically using the form below or by mail or email to:  

Meghan Cline
1445 N Orchard St.
Boise, ID 83706
meghan.cline@deq.idaho.gov

Related Documents

Draft Certification

Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.