PROJECT: Sunnyvale East and West Channels Flood Protection
PUBLIC NOTICE NUMBER: SPN-2017-00281
PUBLIC NOTICE DATE: May 19, 2025
COMMENTS DUE DATE: June 20, 2025
PERMIT MANAGER: Sarah Firestone TELEPHONE: (415) 503-6776 E-MAIL: Sarah.M.Firestone@usace.army.mil
INTRODUCTION:
Santa Clara Valley Water District (Valley Water, POC: Nick Mascarello, (408) 630-3147), 5750 Almaden Expressway, San Jose, California 95118, has applied to the U.S. Army Corps of Engineers (USACE), San Francisco District, for a Department of the Army Permit to implement bridge/culvert improvements, channel improvements, levee modifications, floodwall installation, and modifications to existing maintenance roads adjacent to the Sunnyvale Channels, located in Santa Clara County, California. This Department of the Army permit application is being processed pursuant to the provisions of Section 404 of the Clean Water Act of 1972, as amended (33 U.S.C. § 1344 et seq.) and Section 10 of the Rivers and Harbors Act of 1899, as amended (33 U.S.C. § 403 et seq.).
PROPOSED PROJECT:
Project Site Location: The East Channel's project area runs from 37.3414° latitude, -122.0233° longitude to 37.4173° latitude, -121.9951° longitude. The West Channel's project area runs from 37.3986° latitude, -122.0326° longitude to 37.4194° latitude,
-122.0131° longitude. At the northern end of the project areas, both channels discharge into Guadalupe Slough. The entirety of both project areas is within the City of Sunnyvale, Santa Clara County, California.
Project Site Description: The Sunnyvale Channels were constructed in the 1960’s by Valley Water to help prevent flooding from stormwater. They are largely earthen trapezoidal channels with some reaches armored with rock or concrete. Both channels pass under roads and cross utility lines. Land bordering the project sites consists of residential and commercial developments.
Project Description: As shown in the attached drawings, the proposed project involves sediment removal, channel grading, installation of rock slope protection, and installation of concrete channel lining in both channels. During work within each channel, temporary cofferdams would be installed within the channels. The project also proposes to resurface the existing San Francisco Bay Trail with decomposed crushed granite along three segments of the Bay Trail.
On the East Channel: At Caribbean Drive, the existing dual-span bridge would be completely replaced with a reinforced concrete, triple-cell box culvert bridge. New transitional concrete wingwalls would be constructed along both banks of the East Channel, at both the upstream and downstream sides of this Caribbean Drive culvert crossing. Headwalls would be raised at four roadway crossings (Moffett Park Drive, SR 237, Persian Drive, and Tasman Drive). Approximately 1,150 linear feet of levee would be raised at the downstream end of the project area. In addition, the levees along the from Caribbean Drive to Moffett Park Drive would be widened. Reinforced concrete vertical floodwalls would be constructed from Guadalupe Slough upstream to approximately Interstate 101.
On the West Channel: The existing 9-foot by 10-foot, reinforced concrete box culvert at Carl Road would be completely replaced with a new 10-foot by 15-foot, single-cell, reinforced concrete box culvert. The existing 105-foot single cell reinforced concrete box culvert at West Java Drive would be extended 10 feet upstream and five feet downstream, and concrete wingwalls similar to the existing ones would be constructed at the new inlet and outlet. Headwalls would be raised at four roadway crossings (Caribbean Drive and Bordeaux Drive). Approximately 500 linear feet of levees would be increased in height south of Pond A4 at the downstream end of the West Channel and immediately east of the Sunnyvale Water Pollution Control Plant. Existing levees would be enlarged along the West Channel between Carl Road and Caribbean Drive, along both the east and west banks. Reinforced concrete vertical floodwalls would be constructed from Pond A4 upstream to Carl Road and approximately Caspian Court upstream to Mathilda Avenue.
Basic Project Purpose: The basic project purpose comprises the fundamental, essential, or irreducible purpose of the project, and is used by USACE to determine whether the project is water dependent. The basic project purpose is stormwater flood control.
Overall Project Purpose: The overall project purpose serves as the basis for the Section 404(b)(1) alternatives analysis and is determined by further defining the basic project purpose in a manner that more specifically describes the applicant's goals for the project while allowing a reasonable range of alternatives to be analyzed. The overall project purpose is to provide a 100-year level of flood protection in the City of Sunnyvale.
Project Impacts: Temporary impacts to waters of the U.S. include the installation of temporary dewatering structures and sediment removal. The proposed project would excavate 500 cubic yards of material (riprap, concrete, sacked concrete, and sediment) from 2,146 square feet of the East Channel. The proposed project would result in the discharge of approximately 41,220 cubic yards of fill within 3.4 acres of tidal wetland and approximately 3,433 cubic yards of fill within 1.3 acres of tidal channel. Expansion of culverts would result in the loss of 56 square feet of tidal wetland and 365 square feet of tidal channel, and there would be an expansion of approximately 0.10 acre of exposed hardscape within tidal channels. The installation of 38,600 cubic yards of buried rock slope protection within the channels is anticipated to result in a temporary loss of function within 3.25 acres of tidal wetland, but these wetlands are anticipated to reform naturally once the project is complete.
Proposed Mitigation: Valley Water proposes to use the West Channel Enhancement Project to mitigate for the loss of 56 square feet of tidal wetland and 365 square feet of tidal channel, along with the loss of function due to expansion of hardscape within 0.13 acre waters of the U.S. Valley Water states that this project created 1.1 acre of tidal wetlands 0.15 acre of tidal other waters of the U.S. within the West Channel between Caribbean Drive and Caspian Court. In addition, areas impacted by the installation of temporary dewatering structures or by the installation of buried rock slope protection would be restored to pre-project conditions.
Project Alternatives:
- No Project – This alternative would not require a permit from USACE. Storms greater than a 10-year flood event would continue to overtop channel banks and bridge headwalls, resulting in damage to property and potential loss of life.
- Proposed Project – see project description.
- Levee Enlargement – This alternative has the same components as the proposed project, but the proposed floodwalls would be replaced with increasing the height of the existing levees.
- Pond A4 Detention Basin – This alternative has the same components is the proposed project with the addition of breaching the southern levee of Pond A4 in the San Francisco Bay to reroute both Sunnyvale Channels into Pond A4. Pond A4 would function as a detention basin, and the ponds southern and northeast levees would need to be raised to accommodate the stormwater flows. This alternative would remove tidal influence from both Sunnyvale Channels, slightly reducing the height of 100-year flows within the channels.
- Flood Protection Improvements Only – This alternative includes only the installation of floodwalls, the enlargement of levees, and modifications to culverts and bridges. It does not include bank erosion repairs, sediment removal, concrete channel lining, and maintenance road improvements. Maintenance-level sediment removal would continue as part of the Valley Water Stream Maintenance Program.
- Braly Park Detention Area – This alternative would create an underground storm water detention basin, approximately four acres in size, below Braly Park. High flows would be diverted to the storm water detention basin in order to prevent downstream flooding. Consequently, downstream floodwall height could be slightly reduced. All other components of the proposed project would be included in this alternative.
- Box Culverts with Floodwalls – Existing open channel reaches upstream of Caribbean Drive that are insufficient to contain a 100-year flood would be replaced with buried concrete box culverts designed to contain 100-year flood flows. Approximately five miles of channel would be culverted. Floodwalls would be installed along the channels downstream of Caribbean Drive, as described in the proposed project.
- Biotechnical Bank Stabilization – This alternative would include all components from the proposed project other than the placement of rock slope protection. Instead of rock slope protection, this alternative would install biotechnical bank stabilization such as root wads or wood crib walls.
USACE has not endorsed the submitted alternatives analysis at this time. USACE will conduct an independent review of the project alternatives prior to reaching a final permit decision.
STATE AND LOCAL APPROVALS:
Water Quality Certification: State water quality certification or a waiver thereof is a prerequisite for the issuance of a Department of the Army Permit to conduct any activity which may result in a fill or pollutant discharge into waters of the United States, pursuant to Section 401 of the Clean Water Act of 1972, as amended (33 U.S.C. § 1341 et seq.). The applicant has recently submitted an application to the California Regional Water Quality Control Board (RWQCB) to obtain water quality certification for the project.. No Department of the Army Permit will be issued until the applicant obtains the required certification or a waiver of certification. A waiver can be explicit, or it may be presumed if the RWQCB fails or refuses to act on a complete application for water quality certification within 60 days of receipt, unless the District Engineer determines a shorter or longer period is a reasonable time for the RWQCB to act.
Water quality issues should be directed to the Executive Officer, California Regional Water Quality Control Board, San Francisco Bay Region, 1515 Clay Street, Suite 1400, Oakland, California 94612, by the close of the comment period.
Coastal Zone Management: Section 307(c) of the Coastal Zone Management Act of 1972, as amended (16 U.S.C. § 1456(c) et seq.), requires a non-Federal applicant seeking a federal license or permit to conduct any activity occurring in or affecting the coastal zone to obtain a Consistency Certification that indicates the activity conforms with the state’s coastal zone management program that indicates the activity conforms with the state’s coastal zone management program. Generally, no federal license or permit will be granted until the appropriate state agency has issued a Consistency Certification or has waived its right to do so. Since the project occurs in the coastal zone or may affect coastal zone resources, the applicant has applied for a Consistency Certification from the San Francisco Bay Conservation and Development Commission to comply with this requirement.
Coastal zone management issues should be directed to the Executive Director, San Francisco Bay Conservation and Development Commission, 375 Beale St., Suite 510, San Francisco, CA 94105, by the close of the comment period.
Other Local Approvals: The applicant has applied for the following additional governmental authorizations for the project:
- A California Department of Fish and Wildlife Lake or Streambed Alteration Agreement; and
- A City of Sunnyvale Encroachment Permit, Tree Removal Permit, Construction Traffic Plan Approval, and Temporary Sign Permit.
COMPLIANCE WITH VARIOUS FEDERAL LAWS:
National Environmental Policy Act (NEPA): Upon review of the Department of the Army permit application and other supporting documentation, USACE has made a preliminary determination that the project neither qualifies for a Categorical Exclusion nor requires the preparation of an Environmental Impact Statement for the purposes of NEPA. At the conclusion of the public comment period, USACE will assess the environmental impacts of the project in accordance with the requirements of the National Environmental Policy Act of 1969 (42 U.S.C. § 4321-4347), the Council on Environmental Quality's regulations at 40 C.F.R. § 1500‑1508, and USACE regulations at 33 C.F.R. § 325. The final NEPA analysis will normally address the direct, indirect, and cumulative impacts that result from regulated activities within the jurisdiction of USACE and other non-regulated activities USACE determines to be within its purview of Federal control and responsibility to justify an expanded scope of analysis for NEPA purposes. The final NEPA analysis will be incorporated in the decision documentation that provides the rationale for issuing or denying a Department of the Army Permit for the project. The final NEPA analysis and supporting documentation will be on file with the San Francisco District, Regulatory Division.
Endangered Species Act (ESA): Section 7(a)(2) of the ESA of 1973, as amended (16 U.S.C. § 1531 et seq.), requires Federal agencies to consult with either the U.S. Fish and Wildlife Service (USFWS) or the National Marine Fisheries Service (NMFS) to ensure actions authorized, funded, or undertaken by the agency are not likely to jeopardize the continued existence of any Federally-listed species or result in the adverse modification of designated critical habitat. As the Federal lead agency for this project, the Environmental Protection Agency (EPA) conducted a review of the California Natural Diversity Data Base, digital maps prepared by USFWS and NMFS depicting critical habitat, and other information provided by the applicant to determine the presence or absence of such species and critical habitat in the project area. Based on this review, the EPA consulted with the USFWS and the NMFS to address project-related impacts. The USFWS issued a biological opinion dated December 19, 2022, for impacts to California least tern (Sterna antillarum browni), salt marsh harvest mouse (Reithrodontomys raviventris), and California clapper rail (Rallus longirostris obsoletus). In a letter dated January 26, 2023, the NMFS concurred that the project may affect, but is not likely to adversely affect Central California Coast steelhead (Oncorhynchus mykiss), North American green sturgeon (Acipenser medirostris), and critical habitat for these species.
Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA): Section 305(b)(2) of the MSFCMA of 1966, as amended (16 U.S.C. § 1801 et seq.), requires Federal agencies to consult with the NMFS on all proposed actions authorized, funded, or undertaken by the agency that may adversely affect essential fish habitat (EFH). EFH is defined as those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity. EFH is designated only for those species managed under a Federal Fisheries Management Plan (FMP), such as the Pacific Groundfish FMP, the Coastal Pelagics FMP, or the Pacific Coast Salmon FMP. As the Federal lead agency for this project, the EPA conducted a review of digital maps prepared by NMFS depicting EFH to determine the presence or absence of EFH in the project area. To address project related impacts to EFH, the EPA initiated consultation with NMFS, pursuant to Section 305(5(b)(2) of the Act. In a letter dated January 26, 2023, NMFS concurred with the EPA’s adverse effect determination but had no EFH conservation recommendations.
Marine Protection, Research, and Sanctuaries Act (MPRSA): Section 302 of the MPRSA of 1972, as amended (16 U.S.C. § 1432 et seq.), authorizes the Secretary of Commerce, in part, to designate areas of ocean waters, such as the Cordell Bank, Gulf of the Farallones, and Monterey Bay, as National Marine Sanctuaries for the purpose of preserving or restoring such areas for their conservation, recreational, ecological, or aesthetic values. After such designation, activities in sanctuary waters authorized under other authorities are valid only if the Secretary of Commerce certifies that the activities are consistent with Title III of the Act. No Department of the Army Permit will be issued until the applicant obtains any required certification or permit. The project does not occur in sanctuary waters, and a preliminary review by USACE indicates the project is not likely to affect sanctuary resources. This presumption of effect, however, remains subject to a final determination by the Secretary of Commerce or his designee.
National Historic Preservation Act (NHPA): Section 106 of the NHPA of 1966, as amended (16 U.S.C. § 470 et seq.), requires Federal agencies to consult with the appropriate State Historic Preservation Officer to take into account the effects of their undertakings on historic properties listed in or eligible for listing in the National Register of Historic Places. Section 106 of the Act further requires Federal agencies to consult with the appropriate Tribal Historic Preservation Officer or any Indian tribe to take into account the effects of their undertakings on historic properties, including traditional cultural properties, trust resources, and sacred sites, to which Indian tribes attach historic, religious, and cultural significance. As the Federal lead agency for this undertaking, the EPA conducted a review of the latest published version of the National Register of Historic Places, survey information on file with various city and county municipalities, and other information provided by the applicant to determine the presence or absence of historic and archaeological resources within the permit area. Based on this review, the EPA made a determination that historic or archaeological resources are present in the permit area but that such resources would not be adversely affected by the project (no historic properties affected). The EPA initiated consultation with the State Historic Preservation Officer (SHPO), pursuant to Section 106 of the Act. In a letter dated September 13, 2022, the SHPO did not object to the EPA’s finding of no historic properties affected.
COMPLIANCE WITH THE SECTION 404(b)(1) GUIDELINES:
Projects resulting in discharges of dredged or fill material into waters of the United States must comply with the Guidelines promulgated by the Administrator of the Environmental Protection Agency under Section 404(b) of the Clean Water Act (33 U.S.C. § 1344(b)). An evaluation pursuant to the Guidelines indicates the project is not dependent on location in or proximity to waters of the United States to achieve the basic project purpose. This conclusion raises the (rebuttable) presumption of the availability of a less environmentally damaging practicable alternative to the project that does not require the discharge of dredged or fill material into special aquatic sites. The applicant has submitted an analysis of project alternatives which is being reviewed by USACE.
PUBLIC INTEREST EVALUTION:
The decision on whether to issue a Department of the Army Permit will be based on an evaluation of the probable impacts, including cumulative impacts, of the project and its intended use on the public interest. Evaluation of the probable impacts requires a careful weighing of the public interest factors relevant in each particular case. The benefits that may accrue from the project must be balanced against any reasonably foreseeable detriments of project implementation. The decision on permit issuance will, therefore, reflect the national concern for both protection and utilization of important resources. Public interest factors which may be relevant to the decision process include conservation, economics, aesthetics, general environmental concerns, wetlands, cultural values, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shore erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, considerations of property ownership, and, in general, the needs and welfare of the people.
CONSIDERATION OF COMMENTS:
USACE is soliciting comments from the public; Federal, State, and local agencies and officials; Native American Nations or other tribal governments; and other interested parties in order to consider and evaluate the impacts of the project. All comments received by USACE will be considered in the decision on whether to issue, modify, condition, or deny a Department of the Army Permit for the project. To make this decision, comments are used to assess impacts on endangered species, historic properties, water quality, and other environmental or public interest factors addressed in a final environmental assessment or environmental impact statement. Comments are also used to determine the need for a public hearing and to determine the overall public interest in the project.
SUBMITTING COMMENTS:
During the specified comment period, interested parties may submit written comments to:
Sarah Firestone
San Francisco District, Regulatory Division
450 Golden Gate Avenue, 4th Floor
San Francisco, California 94102-3404
Sarah.M.Firestone@usace.army.mil
Comment letters should cite the project name, applicant name, and public notice number to facilitate review by the Regulatory Permit Manager. Comments may include a request for a public hearing on the project prior to a determination on the Department of the Army permit application; such requests shall state, with particularity, the reasons for holding a public hearing. All substantive comments will be forwarded to the applicant for resolution or rebuttal. Additional project information or details on any subsequent project modifications of a minor nature may be obtained from the applicant and/or agent or by contacting the Regulatory Permit Manager by telephone or e-mail (cited in the public notice letterhead). An electronic version of this public notice may be viewed under the Public Notices tab on the USACE website: https://www.spn.usace.army.mil/Missions/Regulatory