The Idaho Department of Environmental Quality (DEQ) has opened a public comment period regarding a draft Section 401 Water Quality Certification for the Caldera Flats Project in Fremont County.
Agency officials received the certification request on September 3, 2026. The proposed development is situated along two unnamed water bodies within the Henrys Lake Outlet, part of the Upper Henrys subbasin. Project plans call for rerouting a wetland swale and installing two culverts to facilitate residential road crossings.
The DEQ states that compliance with federal permit terms and certification conditions will ensure adherence to state and federal water quality requirements. These include specific sections of the Clean Water Act (301, 302, 303, 306, and 307) and Idaho’s “Water Quality Standards” under IDAPA 58.01.02.
The draft certification document is available for public review at the DEQ State Office in Boise and the Idaho Falls Regional Office. Residents may submit written comments via an online form, mail, or email to Destiny Locke. The comment period closes at 5 p.m. Mountain Time on October 12, 2026.
The project is expected to impact approximately 0.17 acres of waters of the United States, including wetlands. Construction activities are projected to discharge about 115 cubic yards of gravel or rock into the water bodies.
The DEQ’s review is based on regulations found in 40 CFR §§ 121.5 (b) and (c) and 121.7 (c). The agency offers reasonable language access and disability services for documents at no charge to ensure public participation.