PROJECT: Reissuance of Regional General Permit 20 for Salinas River Channel Maintenance Program in Monterey County
PUBLIC NOTICE NUMBER: SPN-1996-223090
PUBLIC NOTICE DATE: August 22, 2022
COMMENTS DUE DATE: September 19, 2022
PERMIT MANAGER: Greg Brown | TELEPHONE: 415-503-6791 | E-MAIL: gregory.g.brown@usace.army.mil
1. INTRODUCTION: The Monterey County Water Resources Agency (MCWRA) (POC: Jennifer Bodensteiner, BodensteinerJM@co.monterey.ca.us, 1441 Schilling Place, North Building, Salinas, California 93901) and Monterey County Resource Conservation District (RCD) (POC: Brandt Bates, 744-A La Guardia Street, Salinas, CA 93905, brandt.bates@rcdmonterey.org) have applied to the U.S. Army Corps of Engineers (Corps), San Francisco District, for reissuance of Department of the Army Regional General Permit 20 (RGP 20) for continuing implementation of Monterey County’s Salinas River Stream Maintenance Program (SMP). RGP 20 authorizes the permittees to conduct annual sediment and vegetation removal from predetermined maintenance areas on sediment bars outside the low flow channel of the Salinas River. Reissuance of the RGP for an additional 5 years would allow continued annual authorization of maintenance activities subject to Corps jurisdiction. With this reissuance, primary responsibility for implementation of the SMP would be transferred from MCWRA to the RCD. This Department of the Army permit reissuance 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.).
2. PROPOSED PROJECT:
Project Site Location: The SMP includes 92 linear miles of the Salinas River in Monterey County, from River Mile (RM) 2 near the State Highway 1 bridge upstream to RM 94 near the town of San Ardo (Figure 1). The project area is divided into 7 River Management Units (RMUs), detailed in Figures 2-8. The SMP area will also include 2 linear miles of 3 Salinas River tributaries: San Lorenzo Creek in King City, Bryant Canyon Channel in Soledad, and Gonzales Slough between Chualar and Gonzales (Figures 9-11).
Project Site Description: The Salinas River flows approximately 180 miles north/northwest from its headwaters in San Luis Obispo County through the Salinas Valley before reaching Monterey Bay near Castroville, California. With a drainage area of approximately 4,240 square miles, the Salinas River watershed is the largest watershed in the central California coast area. Major tributaries to the Salinas River within the Program Area include Arroyo Seco and San Lorenzo Creek. The Salinas River within the SMP area is roughly divided into two reaches based on channel morphology. The lower reach (RM 2.0 - 22.0, which includes RMU 6 and 7), is generally characterized by a narrower channel (typically about 500 to 1000 feet wide); the upper reach (RM 22.0 - 94.0, which includes RMUs 1-5) is relatively wide, with top widths that can exceed 2000 feet. The channel bed in both reaches is typically either flat with little vertical oscillation in topography, or comprised of low amplitude dune-ripples. The channel bed and banks along both reaches are predominantly sand. RMUs along both reaches consist primarily of private agricultural lands that border or extend into the river channel, but also contain bridges, municipal lands and facilities, and other public infrastructure. Additional details on each RMU are provided in Table 1.
Historically, floods likely scoured the sediment bars and channel bottom on a regular basis, removing vegetation and transporting sediments. Since construction of the Nacimiento (1957) and San Antonio (1967) Reservoirs, high flow events have been muted and scouring is less frequent. Low, non-scouring flows are maintained well into the dry season, extending the growing season for vegetation in the primary low flow channel. This vegetation growth has been invigorated in the last few years since the reoperation of Nacimiento Reservoir (2010) to provide sufficient flows at the Salinas River Diversion Facility to meet agricultural demands for groundwater recharge and fish bypass flow requirements.
Non-native invasive plant species have been spreading pervasively in the Salinas River watershed, which has the second largest infestation of arundo (Arundo donax) in the State of California. As of 2012, there were just over 1,470 acres of arundo mapped in the SMP area. Compared to native riparian plants, arundo provides little shading of in-stream habitat and extremely dense vegetation, leading to increased water temperatures and reduced habitat quality for native wildlife. Once established, arundo has the ability to outcompete and suppress native vegetation, and it draws substantially more water from the groundwater aquifer than native vegetation. Because of the density of aboveground biomass and equally dense root structure, large stands of arundo alter the riverine fluvial processes in ways that reduce natural vegetation succession following flow events and alter sediment transport budgets and geomorphic structure. Arundo also increases fire frequency and intensity due to its tall, high fuel load that can burn year round. Other invasive species in the watershed include tamarisk (Tamarix parviflora), pampas grass (Cortaderia selloana), jubata grass (Cortaderia jubata), and Canary Island date palm (Phoenix canariensis). Recent field observations suggest that drought conditions may be facilitating the spread of tamarisk in RMU 1.
Project Description: A pilot project for channel maintenance activities was previously authorized under an earlier RGP and conducted in RMUs 4 and 5 from 2014 thru 2015. RGP 20 was then issued in 2016 to authorize expanded maintenance activities in all 7 RMUs and the 3 tributary reaches, and this work has been successfully implemented for the last 5 years. Reissuance of RGP 20 would allow continued annual authorization of maintenance work within the RMUs, consisting mostly of vegetation management (mowing and discing), sand/sediment management (channel smoothing), and non-native vegetation removal and herbicide treatment of arundo and tamarisk (Figure 12). This would reduce the risk of flooding to adjacent farm fields and prevent bank erosion. Project activities would create and maintain a series of linear “secondary channels” paralleling the existing low-flow channel (Figure 13) and designed to become active during higher flow events (5-year interval or approximately 25,000 cfs). These activities would occur annually, with reduced activity expected over the 5‐year permit period due to 90% of vegetation management occurring in years 1‐2 and spot management in years 3, 4 and 5 as vegetation begins regrowth in the channel. Maintenance activities would occur between October 1 and November 15.
The proposed locations of secondary channels have been preferentially aligned along meander cutoffs, low-lying undeveloped areas, and former river alignments to mimic the historical braiding of the Salinas River. Most secondary channels would meet, or tie-in with, the low flow channel at upstream and downstream locations as would be expected in a more natural braided river channel. Where possible, tie-ins would be located to: (1) avoid or reduce potential impacts to higher value native vegetation (e.g., riparian or wetland areas); (2) in areas where large patches of arundo are found (i.e., to facilitate non-native species removal); (3) in areas where the bank is already low (e.g., 3-5 feet above the bottom of the low-flow channel, versus 6-7 feet); (4) at existing bends (to facilitate natural overbank flow at the upstream end); and (5) aligned to avoid potential impacts to adjacent banks via increased scour. Downstream tie-in points would also be positively graded at the area joining the low flow channel to avoid potential fish stranding. In a limited number of cases (<25%), the geomorphology or hydrology of the river may require tie-ins be located in an area requiring removal of larger sized riparian vegetation (e.g., multiple mid-successional willows greater than 6 inches dbh). In those instances, the tie-in would be made through two to four smaller notches ranging from 15-30 feet wide, rather than one larger opening in the riparian corridor that would result in removal of more trees and a larger riparian impact. Pre-construction staking and flagging would also be used to avoid large-trees, riparian vegetation, and wetlands, where possible, when creating both secondary channels and their connection to the low-flow channel. Areas where arundo dominates the tie-in (> 95% coverage) would be treated to remove all arundo.
In addition to secondary channels, at limited locations within RMUs 6 and 7 (Figure 14), vegetation maintenance and sediment removal activities would occur in focused selective treatment areas (Figure 15), rather than in linear secondary channels. The work in these 2 areas would include removing tree limbs and sandbar material in areas directly adjacent to the low flow channel.
The objective of the proposed management activities within these RMUs is to mimic natural braiding in the Salinas River historically provided by higher, scouring flows, especially in secondary channels. The goal is to increase channel complexity, slow velocities in the primary low flow channel, and encourage a wider range of riparian habitat conditions (earlier to later successional vegetation communities) that would have been present historically.
At the conclusion of each year’s maintenance season, a summary report would be developed by RMU Program Participants and submitted to the RCD for review and approval. RCD would provide the approved Annual RMU Report to permitting agencies, as necessary. The Annual RMU Report would include documentation of maintenance and mitigation actions for the year.
Basic Project Purpose: The basic project purpose comprises the fundamental, essential, or irreducible purpose of the project, and is used by the Corps to determine whether the project is water dependent. The basic project purpose is 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 minimize bank erosion and reduce flood risk to agricultural land adjacent to the Salinas River within the SMP area, while maintaining and enhancing natural habitat and ecological and hydrological processes.
Project Impacts: Up to 130 potential management areas (secondary channel locations and selective treatment areas) have been identified throughout the 7 RMU’s and 3 tributaries, totaling approximately 875 acres. The majority of the proposed work within these management areas would be conducted below the Ordinary High Water Mark (OHWM) of the Salinas River or its tributaries. Maintenance activities in these areas would temporarily impact waters of the U.S. through sediment grading or removal. Approximately 700 acres of native and non-native vegetation types within the management areas could be disturbed by vegetation management and/or sediment removal under the SMP. An additional 155 acres of unvegetated or bare ground may be temporarily disturbed during sediment grading or removal. Up to 554,420 cubic yards (CY) of sediment could be removed annually under the SMP, and no more than 785,000 CY of sediment could be removed in any two consecutive years. Additionally, no more than 450,000 CY of sediment could be removed from any given 1 mile length of river in the upper reach, and no more than 100,000 CY of sediment could be removed over any 1 mile length of river in the lower reach over a consecutive 2 year period. These impacts are considered temporary because of the dynamic nature of the river system, which is anticipated to shift vegetation and sediments within the floodplain during moderate to high flow events. Annual limits on vegetation/grading impacts and sediment removal are summarized below:
SMP Annual Limits of Sediment and Vegetation Removal
Area
|
River Mile1
(RM)
|
Sediment Quantity (CY)
|
Native Vegetation (Acres)
|
Non-Native Vegetation
|
Salinas River Mainstem
|
2.0 – 21.0
|
100,000
|
175
|
No Limit
|
21.0 – 94.0
|
452,200
|
640
|
No Limit
|
Gonzales Slough
|
31.6
|
20
|
10
|
No Limit
|
Bryant Canyon Channel
|
47.1
|
200
|
10
|
No Limit
|
San Lorenzo Creek
|
69.0
|
2000
|
10
|
No Limit
|
TOTAL
|
|
554,420
|
875
|
No Limit
|
1Refer to Table 1 to correlate River Miles with the SMP RMU boundaries. In general, RM 2.0 to 21.0 corresponds to RMUs 6 and 7; RM 21.0 to RM 94.0 generally corresponds with RMUs 1 through 5. RM indicated for tributaries reflects the location of the confluence of the tributary with the Salinas River mainstem.
|
Proposed Mitigation: Impacts to wetland areas would be avoided, and impacts from fill below the OHWM of the Salinas River or its tributaries (grading/smoothing and secondary channel tie-ins) are expected to be temporary. This program is not expected to result in a loss of waters of the U.S. Annual impacts to sensitive habitat and vegetation types in the secondary channels from maintenance activities would be calculated at the RMU-level and would be used to determine annual mitigation needs by type. Mitigation needs would be identified after avoidance and minimization measures have been implemented during pre-maintenance surveys and would primarily consist of revegetation of disturbed areas. These would be tracked for each secondary channel and reported in the Annual RMU Report.
3. 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 Central Coast Regional Water Quality Control Board (RWQCB) issued a water quality certification on August 31, 2016, for the initial issuance of RGP 20, and this certification will remain valid through November 30, 2025.
Water quality issues should be directed to the Executive Officer, California Regional Water Quality Control Board, Central Coast Region, 895 Aerovista Place, Suite 101, San Luis Obispo, California 93401, 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. 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. The project does not occur in the coastal zone, and a preliminary review by USACE indicates the project would not likely affect coastal zone resources. This presumption of effect, however, remains subject to a final determination by the California Coastal Commission.
Coastal zone management issues should be directed to the District Manager, California Coastal Commission, Central Coast District Office, 725 Front Street, Suite 300, Santa Cruz, California 95060-4508, by the close of the comment period.
4. 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, USACE has completed section 7 consultation with NMFS and USFWS to address potential project-related impacts to the following listed species:
- Steelhead (Oncorhynchus mykiss)
- California tiger salamander (Ambystoma californiense)
- California red-legged frog (Rana draytonii)
- Least Bell’s Vireo (Vireo bellii pusillus)
- Southwestern willow flycatcher (Empidonax traillii extimus)
- Yellow-billed cuckoo (Coccyzus americanus)
- San Joaquin Kit Fox (Vulpes macrotis mutica)
NMFS issued a letter of concurrence on September 6, 2016, to address potential impacts to steelhead, and USFWS issued a biological opinion on August 22, 2016. Both consultations considered implementation of the SMP for a 10 year period, from the 2016 maintenance season through the end of the 2025 maintenance season.
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, USACE has conducted a review of digital maps prepared by NMFS depicting EFH to determine the presence or absence of EFH in the project area. Based on this review, USACE has made a preliminary determination that EFH is not present at the project location or in its vicinity, and that consultation will not be required. USACE will render a final determination on the need for consultation at the close of the comment period, taking into account any comments provided by NMFS.
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, USACE has conducted a review of 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, USACE has made a preliminary determination that historic or archaeological resources are not likely to be present in the permit area, and that the project has no potential to cause effects to historic properties. USACE will render a final determination on the need for consultation at the close of the comment period, taking into account any comments provided by the State Historic Preservation Officer, the Tribal Historic Preservation Officer, the Advisory Council on Historic Preservation, and Native American Nations or other tribal governments. If unrecorded archaeological resources are discovered during project implementation, those operations affecting such resources will be temporarily suspended until USACE concludes Section 106 consultation with the State Historic Preservation Officer or the Tribal Historic Preservation Officer to take into account any project related impacts to those resources.
5. 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 previously submitted an analysis of project alternatives which was reviewed by USACE, and it was determined that the existing SMP represents the least environmentally damaging practicable alternative.
6. PUBLIC INTEREST EVALUTION: The decision on whether to reissue 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.
7. 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.
8. SUBMITTING COMMENTS: During the specified comment period, interested parties may submit written comments to Greg Brown, San Francisco District, Regulatory Division, 450 Golden Gate Avenue, 4th Floor, San Francisco, California 94102-3404; 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.