SUBJECT: The U.S. Army Corps of Engineers, Albuquerque District, (Corps) and the New Mexico Environment Department’s Surface Water Quality Bureau (SWQB) are evaluating an application for the Los Lunas RM 163 Conveyance Capacity Project, located in Los Lunas, Valencia County, New Mexico, which would result in impacts to approximately 14.06 acres and 8,783 linear feet of waters of the United States in or adjacent to the Rio Grande. This notice is to inform interested parties of the proposed activity and to solicit comments
AUTHORITY: This application is being evaluated under Sections 404 and 401 of the Clean Water Act (CWA) for the discharge of dredged or fill material in waters of the United States (U.S.). State water quality certification is provided under the authority of 20.6.2 New Mexico Administrative Code.
APPLICANT: Jennifer Faler
U.S. Bureau of Reclamation
555 Broadway Blvd. NE
Albuquerque, New Mexico 87102
AGENT: Ann Dement
U.S. Bureau of Reclamation
555 Broadway Blvd. NE
Albuquerque, NM 87102
LOCATION: The project site is located on the Rio Grande, within Section 23, Township 7 North, Range 2 East, latitude 34.818413°, longitude
-106.71286°, Los Lunas, Valencia County, New Mexico
PROJECT DESCRIPTION: The applicant’s proposed project components consist of five bank-lowering polygon areas within the historic channel and one relic berm removal in the eastern historic floodplain of the Rio Grande. These project components will improve the channel conveyance by increasing the width of the river on both the west and east banks. The relic berm will also be removed as it has been holding water on the floodplain against the levee and preventing the water from flowing downstream. Based on the available information, the overall project purpose is to improve river conveyance capacity and reduce flood risk. The applicant believes there is a need to reduce the water surface elevation (WSE) by increasing channel capacity to lower the flooding risk, protect the levy, and improve the ecological function. The attached drawings provide additional project details.
PROPOSED MITIGATION: Mitigation is an important part of the U.S. Army Corps of Engineers permitting process. Mitigation is sequential and includes avoidance, minimization, and compensation for unavoidable adverse impacts to aquatic resources. A detailed mitigation plan is not required for issuance of a public notice, but all three aspects of mitigation must be adequately addressed prior to any Corps permit decision. Currently, the applicant is proposing the following mitigation for their proposal:
The proponent proposes that the project will function as a self-mitigating initiative, offering both flood risk reduction and a net ecological benefit. The project is designed to enhance the main channel of the Rio Grande by lowering the adjacent banks and bars that have accumulated over time. This alteration will maintain the natural hydrology of the river system while increasing the frequency of inundation in the newly lowered areas, thereby fostering the development and sustainability of wetlands.
The project involves widening the channel and creating terraces at various elevations. This design will adapt to flow and sediment inputs, promoting a diverse range of hydraulic conditions, including shallow waters that are beneficial for the Rio Grande silvery minnow (RGSM). By increasing the main channel's capacity, the project will improve flood flow conveyance, reduce overbanking, alleviate stress on levees, and address issues related to prolonged overbanking in the Los Lunas reach.
OTHER AUTHORIZATIONS:
Under Section 401 of the Clean Water Act (CWA), the Corps cannot issue a permit to conduct any activity that may result in a discharge into waters of the United States unless a Section 401 water quality certification (WQC) is granted, verifying compliance with water quality requirements, or WQC is waived. The New Mexico Environment Department Surface Water Quality is the certifying authority responsible for making the WQC decision on this proposal.
ADDITIONAL INFORMATION:
Environmental Setting. There are approximately 14.06 acres of palustrine emergent (PEM1A) wetlands that are waters of the U.S. within the proposed project area and there are approximately 8,783 linear feet of perennial river (i.e., Rio Grande) that are waters of the U.S. within the proposed project area. The proposed site is characterized by occurring within the Rio Grande surface and groundwater basins. The river mile (RM) 163 project site is within the Los Lunas sub-reach, a section of the Middle Rio Grande (MRG) river extending from Isleta Diversion Dam (RM 169) to the community of Los Chaves (RM 153). This sub-reach has a unique topography involving a semi-perched channel where the banks are higher in elevation than the adjacent floodplain and spoil levee toes, but the channel bed remains lower than the levee toes. The levees are non-engineered spoil levees. During high flows these conditions result in saturated levee toes (which can lead to levee failure) and water stranding within the floodplain.
Alternatives. Alternatives to the proposed project are analyzed to identify the least environmentally damaging practicable alternative that meets the applicant’s project purpose and need. Practicability is based on cost, logistics, and technology. All project alternatives, including those which may be less damaging to the aquatic environment, will be considered. The applicant has provided information concerning project alternatives.
No Action: This alternative was not considered because the danger of increased overtopping of the levees is too great of a risk to public safety.
Preferred Alternative: The preferred alternative aims to balance flood risk reduction with ecological benefits, improving overall water management and supporting the health of the riparian environment. The preferred alternative has two components to the project.
1. Bank Lowering: Five bank lowering segments have been identified within the inset floodplain. These segments are concentrated in narrower sections of the river and are designed to increase channel capacity and facilitate better water conveyance. The exact areas for bank lowering will be determined based on design modeling, which will refine the necessary extent to meet water conveyance goals.
2. Berm Removal: A relic berm located just downstream of the Bosque Farms wastewater outfall has been identified for potential removal. This action aims to improve historic floodplain drainage and reduce water depth against the levee.
Alternative 1: Historic bank lowering would cut down the “natural levees” and place the spoils in the low spots next to the levees. This activity would lower the water surface elevation by providing additional flow area. Other benefits would include removing invasive species that are concentrated on the historic bank in this sub-reach and working towards the ideal river cross section where the banks are lower than the floodplain. Historic bank lowering would not be included because the risk of increased overtopping is too great, and the alternative option of fully resetting the cross section has too great of environmental impacts, including vegetation removal and wetland impacts.
Alternative 2: Floodplain drainage features redirect flows into the main channel from the low spots next to the levee. A small side channel would be excavated extending from a low spot next to the levee to the main channel, entering the main channel at an elevation where a 3,500 cfs flood will not back up and inundate the low spot next to the levees. The spoils from the small side channel would be used to build a berm on the downstream side of the side channel. The berm would be designed to catch and redirect all flood flows up to 6,000 cfs. The required length of the channel would require significant removal of vegetation in the bosque. Floodplain drainage features would not be included because the option has too great of environmental impacts, including vegetation removal and future maintenance that could affect wetlands developed within the drainage features.
Alternative 3: Mowing and root raking and decreasing the roughness during flood flows would improve water conveyance and lower the water surface elevation. The roughness can be decreased by mowing vegetation and root raking within the inset floodplain. Mowing by itself would likely stimulate new growth and possibly result in increased roughness within a few years. Root raking decreases the new growth but doesn’t remove it altogether. The water conveyance benefits of mowing and root raking are too temporary to be considered cost-effective by the Bureau of Reclamation. The habitat benefits may be worth the cost, but there are a lot of risks in performing the program effectively.
Alternative 4: Cottonwood tree removal would decrease the roughness of the floodplain during flood flows and would improve water conveyance and lower the water surface elevation. The roughness can be decreased by removing the juvenile cottonwood patches throughout the inset floodplain. To prevent regrowth, the root structure would also need to be removed. The minimal water conveyance benefits of removing cottonwoods on higher ground within the inset floodplain are not considered cost-effective by the Bureau of Reclamation, and the regulatory process may pose a roadblock.
HISTORIC PROPERTIES: The Bureau of Reclamation (BOR) is the lead agency for Section 106 of the National Historic Preservation Act (NHPA) compliance and the USACE is a cooperating agency. If the public has any comments or concerns about historic properties being affected by the BOR’s project, the public should directly contact the BOR point-of-contact identified in this Public Notice.
ENDANGERED SPECIES: The BOR is the lead agency for Section 7 of the Endangered Species Act (ESA) compliance and USACE is a cooperating agency. A Final Biological and Conference Opinion for BOR, Bureau of Indian Affairs, and Non-Federal Water Management and Maintenance Activities on the Middle Rio Grande, New Mexico Consultation Number 02ENNM00-2013-F-0033, was issued on December 2, 2016. This project falls under this Biological Opinion which addresses impacts to threatened and endangered species.
EVALUATION FACTORS: The decision whether to issue a permit will be based on an evaluation of the probable impacts, including cumulative impacts, of the described activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefit, which reasonably may be expected to accrue from the described activity, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the described activity will be considered, including the cumulative effects thereof; among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, consideration of property ownership and, in general, the needs and welfare of the people. The activity's impact on the public interest will include application of the Section 404(b)(1) guidelines promulgated by the Administrator, Environmental Protection Agency (40 CFR Part 230).
FLOODPLAIN MANAGEMENT: The Corps is sending a copy of this public notice to the local floodplain administrator. In accordance with 44 CFR part 60 (Flood Plain Management Regulations Criteria for Land Management and Use), the floodplain administrators of participating communities are required to review all proposed development to determine if a floodplain development permit is required and maintain records of such review.
COMMENT SUBMITTAL AND DEADLINES: The Corps and SWQB are soliciting comments from all interested parties to consider and evaluate the impacts of this proposed activity. Any comments received will be considered to determine whether to issue, issue with special conditions, or deny a permit for this proposal.
Submittal of Corps Permit Application Comments: All comments regarding the Corps permit application for the above-described project must be received on or before September 30, 2024, which is the close of the comment period. Comments on state Section 401 certification must be submitted as described below under “Water Quality Certification Comments”. Extensions of the comment period may be granted for valid reasons provided a written request is received by the limiting date. If no comments are received by that date, it will be considered that there are no objections. Anyone may request, in writing, that a public hearing be held to consider this application. Requests shall specifically state the particular reason(s) for holding a public hearing. If the Corps determines that the information received in response to this notice is inadequate for thorough evaluation, a public hearing may be warranted. If a public hearing is warranted, interested parties will be notified of the time, date, and location. Comments and requests for additional information on the Corps permitting action should be submitted to:
Forrest Luna, Project Manager
US Army Corps of Engineers, Albuquerque District
New Mexico & NW Texas Branch, Albuquerque Office
4101 Jefferson Plaza NE
Albuquerque, New Mexico 87109-3435
Telephone: (505) 342-3678
E-mail: Forrest.Luna@usace.army.mil
Submittal of Water Quality Certification Comments: This notice serves to notify the public that the SWQB will consider issuing a certification under Section 401 of the CWA. The purpose of such certification is to reasonably ensure that the permitted activities will be conducted in a manner compliant with applicable New Mexico water quality standards, including the antidegradation policy, and the statewide water quality management plan. This Notice, including notice of the 30-day public comment period, is also posted on the SWQB website at: https://www.env.nm.gov/surface-water-quality/public-notices/
SWQB will accept and consider written comments regarding the state certification received during the public comment period. Comments may be submitted electronically (preferred) or by hard copy to:
Watershed Protection Program Manager
New Mexico Environment Department SWQB
P.O. Box 5469
Santa Fe, NM 87502-5469
Telephone: 505-827-2793
FAX 505-827-0160
E-mail: wpsprogram.manager@env.nm.gov
Please note that names and addresses of those who submit comments in response to this public notice may be made publicly available through the Freedom of Information Act, the New Mexico Inspection of Public Records Act, or both.