17_WSOF_MM20_2024-08-19.docx

Comment by Fish, Teresa L: This is not the correct banner. It should have the park's name included. Please see the banner for the Peninsula Connector WSOF for the correct one.

WETLAND STATEMENT OF FINDINGS FOR

DIRECTOR’S ORDER #77-1: WETLAND PROTECTION

Cuyahoga Valley National Park (PMIS 224822)

Stabilize Riverbank at Towpath MM 20 South (STA 940) along the Cuyahoga River Cuyahoga Valley National Park, Brecksville, Ohio

Recommended

Superintendent, Cuyahoga Valley National Park Date

Certified for Technical Accuracy and Servicewide Consistency:

Chief, Water Resources Division Date

Approved

Director, Interior Regions 3, 4, 5 Date

Introduction

This Wetland Statement of Findings (WSOF) characterizes the wetland resources that occur within the Cuyahoga Valley Mile Marker (MM) 20 South stabilization project site along the Cuyahoga River, Cuyahoga Valley National Park (CVNP or Park), Cuyahoga County, Ohio. The WSOF describes the impacts the project will likely have on the aquatic resources and documents the steps the National Park Service (NPS) will take to avoid, minimize, and offset these impacts. Comment by Trimbath, Ryan J: The NPS uses the acronym CUVA as the 4-letter abbreviation. CVNP is typically used by the public so it will be familiar however consider using CUVA for consistency with NPS standard. Comment by Ryan Trimbath: I changed them all to CUVA. Accept or reject Comment by Keli Stambaugh: We used CVNP on the Peninsula WSOF, do we want to change it here and moving forward? Comment by Jennifer Clark: Using CVNP per 8/1/2024 meeting.

The NPS proposes to implement riverbank stabilization measures at the MM 20 South site along the Cuyahoga River (Figure 1).

Figure 1. MM 20 South Project Location, Brecksville, Ohio

Stabilization action is needed because the riverbank, visitor and NPS staff safety, and continued viability of the Ohio & Erie Canal Towpath Trail are threatened by active erosion and lateral widening of the river. Instability can develop quickly along the eroding bank and lead to excessive settling causing potential failure and closure of the Towpath Trail. The Towpath Trail runs the length of the Park from north to south and is identified as one of the CVNP’s fundamental resources and values (NPS 2013). This proposed MM 20 South project is one of nine sites identified in need of bank armoring and proposed for construction on the lowland reach of the Cuyahoga River. Consultants hired by the NPS conducted analyses to develop bioengineered Schematic Design (SD) solutions for each of these nine sites (Figure 2).

Figure 2. All nine shoreline project locations along the Cuyahoga River, including MM 20 South.

To date, five sites have been completed and have been successful at meeting the project goals of bank stabilization, protecting critical Park infrastructure, and “no net loss” of wetland functions or values. Two of the nine sites, Peninsula Connector and Milepost (MP) 59.3, are currently under construction.

Because the proposed action would include work in wetlands, this WSOF is required to comply with NPS Director’s Order #77-1: Wetland Protection, which establishes the policies, requirements, and standards for implementing Executive Order 11990 (Protection of Wetlands).

This WSOF describes (1) the proposed project and alternatives; (2) effects of the proposed project on wetlands, as defined in the NPS Procedural Manual #77-1: Wetland Protection; (3) mitigation measures that avoid, reduce, or compensate for adverse effects of the project on wetlands; (4) how the project and mitigations ensure “no net loss” of wetland functions or values; and (5) the cumulative effects of the eight additional armoring projects.

This document focuses on the adverse impacts on the riverine wetlands of the MM 20 South stabilization project and is one of the nine projects that will continue to stabilize the shoreline and prevent future erosion along the Cuyahoga River to meet safety speculations. It is estimated that these nine projects will stabilize over 9,000 feet (1.7 miles) of the riverbank in the 26-mile reach within the Park (Figure 2). A Categorical Exclusion was issued for this project that tiered off the 2004 River Management Plan Environmental Assessment (NPS 2004). A Programmatic Environmental Assessment (EA [NPS 2004]) was developed to evaluate the potential environmental impacts of the proposed Riverbank Management Program as compared to the existing Riverbank Stabilization Program in accordance with the requirements of the National Environmental Policy Act (NEPA), the Council on Environmental Quality (CEQ) regulations of 1978, NPS Management Policies, and NPS Director’s Order #12.

The Purpose and Need for the Action

The Proposed Action stabilizes a section of the Cuyahoga riverbank to protect the existing Towpath Trail. The need for the Proposed Action is to ensure the safety of NPS visitors and staff and for the protection of recreational resources due to the erosional effects resulting from the hydraulic and geomorphic processes of the Cuyahoga River.

The CVNP Region has received, on average, more rain since the 1940’s based on monitoring stations in Akron, Cleveland, Chardon, and Ravenna (National Weather Service). The increased rainfall and river discharge promotes greater erosion rates on unstable banks, such as MM20, which continues in a degradational trend towards the Towpath Trail. Comment by Fish, Teresa L: Figure 3 is not referenced in the document anywhere. Comment by Keli Stambaugh [2]: removed

Fluvial processes of rivers work to erode and deposit materials along their streambanks and valleys. The Cuyahoga River along the project reach is more erosive than depositional and thus, these factors are unbalanced. Particularly, the right-descending (east) bank is the location of active erosion putting the Towpath Trail in danger of damage while alluvial material is being deposited on the left-descending (west) bank, forming a point bar (Figure 3).

Figure 3. MM 20 South meander (looking south) showing proximity of the Cuyahoga River to the Towpath Trail.

Since the Towpath Trail is within the active floodplain and the historic meander belt-width of the river, damage to the trail is anticipated in the near future. This projection is evidenced by low elevation and existing wetland in the valley across the trail from the river. Continued and accelerated erosion is expected as the vertical banks lack vegetation and soil types resistant to scour. As the lateral migration continues point bar development along the left bank facilitates the continued movement to the east. Furthermore, the lateral migration of the right bank has begun to flank a previously installed rock spur at the downstream end of the project site. This rock protrusion now causes a constriction to flow and works against the geometry creating a back eddy circulation of water which promotes additional erosion and risk. Protection of the toe slope and stabilization of the river geometry is critical for bank stability and river function through the meander.

Geotechnical analysis used subsurface soil data and topographic riverbank data for input into Discontinuity Layout Optimization (DLO) modeling software. Results indicated that bank stability in the existing condition did not satisfy the minimum safety requirements. The Towpath Trail is in protected historical districts and is a valuable resource for the public, being a popular means by which most visitors experience the CVNP. Providing a stable shoulder for the Towpath Trail by stabilization of the riverbank at MM 20 South would ensure safe use along a primary overland route adjacent to the river and allow visitors to continue to experience and enjoy the entirety of the Park and the access it provides.

In summary, the existing unstable bank condition and continued trajectory of erosion are threatening the cultural and recreational resources as defined in the need for action.

Proposed Action

To address the need for the action described above, the NPS proposes implementing riverbank stabilization measures at the MM 20 South site along the Cuyahoga River. The project aims to restore the river to a previous channel geometry but with a more resistant boundary condition to protect the Towpath Trail from lateral migration of the river. Design includes installing a keyed rock toe along the meander's outer bend and filling the bank with alluvial material to re-establish the approximate historic meander planform. Material will be faced by the keyed rock toe and capped with topsoil, utilizing bioengineering through coir fabric placement and live cutting installations along the bankfull elevation. This will create a transition from the rock toe to the bankfull bench. The depth of the rock toe key is not deep enough to prevent undercutting based on the most conservative scour analyses. The team implemented a design strategy to counteract the scour depth potential, by adding a sacrificial riprap mass below the average low-flow water surface elevation. This sacrificial riprap will launch/fall into the scour hole, should undercutting to the key trench develop. Additional roughness elements, principally including wood, will also be incorporated into the rock toe as materials are available and as the site allows. Wood provides added habitat value, creating refugia for biota, helping to keep pools open, and the thalweg of the channel away from the rock toe through added roughness. Lastly, a native vegetation buffer will be established consisting of diverse herbaceous species, live stakes and containerized trees.

MM20 Permanent Stream Impact 1.14 AC, 537 LF

FEET

MM20 Temporary Impact 0.15 AC

Figure 4. MM 20 South project showing the limits of disturbance. The yellow polygon indicates permanent impacts (1.140 acres), and the red polygon indicates temporary impacts on the riverine wetland within the site access route (0.150 of an acre). Comment by Fish, Teresa L: Figure 4 should be placed after the paragraph where it's first mentioned, not before.

On the west side of the Towpath Trail, timber mats will be used to traverse other delineated wetlands as equipment follows the existing streambank to the south and west. The access path will then cross over the river in the shallower riffle area to gain access to the inside bend of the stream, known as the point bar. This crossing will be established using a combination of existing river substrate and imported rock for a ford crossing. This access route has been designed to avoid impacts on woody vegetation wherever possible (Figure 5). Only one standing dead tree with a diameter at breast height (DBH) of 24 inches and two shrubs, each with an approximate DBH of 3 inches, are proposed for removal.

Figure 5. MM 20 South access and staging Water control will be a key aspect of Phase I staging and access. Currently, the plan identifies a proposed baseflow diversion channel across the existing point bar. Diverting the baseflow as much as possible around the active work site will minimize the transport of fine sediments downstream during construction disturbance.

Phase II – Site Preparation, Phase III – Bank Stabilization, and Phase IV – Site Restoration

Once Phase I activities have been completed, additional clearing and grubbing of trees/plant material will occur along the banks, and a rough subgrade will be cut to remove any loose or unsuitable material. Comment by Fish, Teresa L: Figure 6 should be placed after the paragraph where it's first mentioned, not before.

After Phase II activities have been completed, imported sandstone material will be placed along the toe location and choked with excavated material cut from the existing point bar. The remaining excavation from the inside point bar will be used to infill the restored bank behind the rock toe and be bucket compacted (Figure 6). Rock keys will then be installed at locations identified on the plan set to prevent flanking of the rock toe (Figure 7). Imported topsoil will be then placed on top of the subgrade to provide a suitable base for plant growth on the restored bank. All exposed topsoil will be wrapped in an erosion-control fabric and planted during Phase IV activities. Comment by Fish, Teresa L: Figure 7 should not come before Figure 6. The labels need to be switched in the paragraph and the figure images, and the images may need to be switched as well. Also, both figures should be placed after the paragraph where they're first mentioned, not before.

Figure 6. Rock toe and bench detail

Figure 7. Rock trench key detail

Site restoration activities will include seeding and planting disturbed areas with Park-approved native plant species. Live stakes and native seed will be planted along the restored bank during the seasonally appropriate planting window. The intent of the project schedule is to coincide the completion of construction activities with a planting window so that planting can be completed immediately.

Alternatives Analysis

Alternative: No Action Alternative

Under the No Action Alternative, the bank adjacent to the Towpath Trail would not be stabilized. The threat of riverbank erosion to the Towpath Trail would continue and not be addressed. This alternative was dismissed because it would not protect the trail (which is a fundamental Park resource), erosion of the riverbank would continue to occur, and it would not address the purpose and need for the project.

Alternative: Direct Measures

Direct measures would only be implemented when the Towpath Trail is in immediate danger of being damaged or destroyed due to a combination of the failing geotechnical conditions and erosional river processes. Measures would be limited to those that repair the bank directly adjacent to the threatened feature and would typically consist of a riprap toe constructed approximately to the mean annual flood elevation, and a variety of bioengineering measures above that point to the top of the eroded bank. Where erosion moves too close to the Towpath Trail or before riverbank stabilization measures can be constructed, fencing would be installed to protect NPS staff and visitors until such construction can be accomplished. Direct construction measures may require the removal of healthy hardwood trees and shrubs on the banks.

NPS has already employed direct measures at this site around 2019, including installing riprap along the reach. Observations made at the site showed the presence of riprap had been placed in the immediate failure area west of the Towpath Trail. The previous attempts at direct measures to stabilize the bank and stop erosion were ultimately not successful due to the limits of rock placement with respect to the changing meander geometry. The scale of the river adjustment surpassed and began to “flank” the upstream limits of the previous stabilization efforts. This is largely one reason that the current proposed action has extended upstream and designed a new meander geometry to counteract this erosion trajectory. The previous efforts slowed the erosion in the immediate concern area for the trail but for long-term protection the extents and design were not sufficient.

Site Description - Wetlands Comment by Trimbath, Ryan J: A map of these features should be included (streams and wetlands) possibly add to figure 1. Comment by Jennifer Clark: Elise? Comment by Elise Bartelme: I pulled a snip from the ES map. I also did this for Fitzwater

Wetland Delineation

HDR, an architecture and engineering firm, performed an initial wetland delineation in the summer of 2021 that included multiple areas along the Cuyahoga River and adjacent corridor within CVNP (HDR 2022a). During November and December 2022, EnviroScience, Inc. (ES), an environmental consulting firm, performed a wetland delineation within the proposed project site. The delineation was performed by Elise Bartelme and Carolyn Krause who are both experienced delineators. Ms. Bartelme is a professional wetland scientist and a signature page denoting their approval of the delineation is included with the report (HDR 2022a; EnviroScience, Inc. 2023). This delineation covered approximately 700 feet along the Cuyahoga River and included the construction, staging, and access areas for MM 20 South (HDR 2022a; EnviroScience, Inc. 2023). Two wetlands were identified within the MM 20 South project reach: Wetland complex B16/17/18 (by HDR) and Wetland W-9 (delineated by ES) (Figure 8). Wetlands were categorized using the Ohio Rapid Assessment Method (ORAM [Mack 2001]). Based on this assessment, Wetlands B16/17/18 and W-9 were identified as Category 2 wetlands. Wetland in these categories account for 65% of coverage within the MM 20 project site in CVNP.

Figure 8. Site map of wetlands and other water resources at MM 20 The proposed site access and construction activities are designed to minimize and avoid impacts to the greatest extent possible. No permanent impacts to onsite wetlands will occur. However, travel through Wetland Complex B16/17/18 is necessary. Timber mats will be used as the primary means to avoid and minimize impacts to onsite wetlands. Typically, timber mats are not considered a permanent or temporary impact to wetlands and are routinely used for construction access. They are not a permanent feature and will be removed when construction is complete. However, USACE will consider timber mats a temporary impact for this project due to potential shrub clearing within the access. The construction area will be accessed using the existing Towpath Trail and staging will use an existing gravel road parallel to the trail. The access begins at Highland Road and continues south along the trail until it reaches the project site. Access to the site then turns west through Wetland Complex B16/17/18. As stated above, the access route through this wetland will require using timber mats but is also routing around existing trees to minimize tree clearing as much as possible.

Unnamed Tributary to the Cuyahoga River – Riverine Stream B13 (HDR)

Unnamed Tributary (UNT) to the Cuyahoga River is a National Hydrography Dataset (NHD) mapped perennial waterway in the MM 20 South site. This stream is in the Boston Run-Cuyahoga River Hydrologic Unit Code (HUC) 12 sub-watershed (HUC#: 04110002-04-05). No potential impacts on the river reach were observed. Stream B13 originates at a head cut, exhibiting evidence of groundwater seepage within the Palustrine Forested Wetland (PFO) portion of the B16/17/18 wetland complex. Iron oxide precipitate and sheen were observed within this channel and dominant substrates include silt and clay. The Headwater Habitat Evaluation Index (HHEI) is a rapid assessment method used to evaluate quality of streams with drainage areas less than one square mile in size (Ohio EPA 2020). Using the HHEI, Stream B13 within the project reach scored 60 and was assessed as having rheocrene potential. A rheocrene stream is defined as having the potential to originate from a natural spring and having a well-defined channel, and a very small drainage area (<0.1 mi2 [Ohio EPA 2020]). Stream B13 is flowing, has a defined channel, and includes a very small drainage area. Comment by Fish, Teresa L: What is PFO? Please make sure to spell out fully before using abbreviations.

Cuyahoga River – Riverine Stream B-19 (HDR)

The Cuyahoga River (Stream B-19) is an NHD-mapped perennial waterway in the MM 20 South site. Stream B-19 is in the Boston Run-Cuyahoga River HUC 12 sub watershed (HUC#: 04110002-04-05). No observable human-induced impacts on the river reach were observed but there is presence of abandoned utilities in the project area. Through field investigation and coordination with the Ohio Utilities Protection Service (OUPS), the following utilities were found within the project limits and have been identified within the contract drawings: fiber optic line — utility owner unknown, out of service coaxial line — AT&T Transmission/Metro. Comment by Trimbath, Ryan J: I believe there is a utility that runs through this project site. The ROW is marked and a pipe is exposed. Was this observed or considered? I can confirm with a site visit if needed but I am pretty confident there is a utility crossing the river at this site. Comment by Jennifer Clark: Jim is this accurate? Comment by Jennifer Clark: What Julie and I were able to find is a statement that says: "Through field investigation and coordination with the Ohio Utilities Protection Service (OUPS), the following utilities were found within the project limits and have been identified within the contract drawings: fiber optic line--utility owner unknown, out of service coaxial line--AT&T Transmission/Metro. Comment by Elise Bartelme: The statement was originally pulled from the HDR report and comments directly on what is observed within the stream. Could include the utility information if you would like.

The river is associated with a well-defined channel and the substrate within the project reach is predominantly cobbles, gravel, sand, and silt. The riverine habitat is classified as a lower perennial riverine system with an unconsolidated bottom that is permanently flooded (R2UBH). Ohio EPA has established the Qualitative Habitat Evaluation Index (QHEI) as a method for evaluating stream habitat quality for streams with a drainage area of one square mile in size or greater (Ohio EPA 2006). The index provides a measure of habitat that generally corresponds to physical factors that affect fish and other important aquatic life including invertebrates. Using the QHEI (Ohio EPA 2006), the Cuyahoga River (B-19) scored 71.5 and therefore was categorized as Good Warmwater Habitat (WWH).

The QHEI conducted by HDR within the limits of the project reach is comparable with the study completed along this reach of the river by the Ohio Environmental Protection Agency (EPA). Ohio EPA sampling locations included two sites within the Cuyahoga River that bracket the project area (RM 25) with a site upstream and downstream at RM 26.50, within the Boston Run-Cuyahoga River watershed and RM 24.1 in the Willow Lake-Cuyahoga River watershed (HUC#: 04110002-05-05). These sites have been sampled by Ohio EPA since the 1980’s and were most recently surveyed in 2017. Along this reach, the Cuyahoga River was deemed to be in partial to full attainment with a listed impairment of a dam/impoundment, causing a barrier to fish passage. However, this dam has since been removed as of 2020 and the Ohio EPA has recommended the site to be in full attainment and recommends classification of the Cuyahoga River from Tinkers Creek to Brandywine Creek as Exceptional Warmwater Habitat including at RM 24.1 (Ohio EPA 2023). Comment by Trimbath, Ryan J: This dam was removed in 2020 and there is no longer an impairment from the dam pool and fish passage is clear. Per the cited report OEPA has recommended the section downstream of the project area now meets Exceptional Warmwater Habitat criteria and is proposing a change in Aquatic Life Use for the section Tinkers creek to Brandywine Creek be changed to EWH (See Ohio EPA TSD pg 274). The project area is just upstream of Brandywine and is designated WWH as stated in the report. Comment by Trimbath, Ryan J: Cuyahoga-TSD.pdf (ohio.gov) Comment by Trimbath, Ryan J: Note their have been more surveys conducted since then which have shown fish are migrating upstream from the historic dam. The fish community has/is continuing to change through this reach. However, there is not a report I can share with you now (USGS, USEPA and USACE are working this site in association with gorge dam removal studies). With that said, it is my professional opinion that updated information would not impact the WSOF overall. Comment by Jennifer Clark: Elise to review Comment by Elise Bartelme: What Ryan added is good. Citation for Ohio EPA added

The Index of Biotic Integrity (IBI) assesses the health of fish populations in streams through the evaluation of in-situ environmental conditions (Ohio EPA 2015). Similarly, the Invertebrate Community Index (ICI) measures the health of the macroinvertebrate community within streams (Ohio EPA 2015). The upstream site at RM 26.1 has a designated aquatic life use (ALU) of WWH, an IBI score between 39 to 40 (indicating ‘fair’ to ‘good’ stream condition), an ICI of 34 to 50 (‘good’ to ‘exceptional’), and a QHEI of 77.75 to 82.5 (‘excellent’ range [Ohio EPA 2023]). Chemical and physical water parameters were not specifically measured within the Boston Run-Cuyahoga River watershed; however, the Ohio EPA found minimum Dissolved Oxygen (DO) exceedances upstream and downstream of the project site at RMs 17.3 and 75.83. Low stream flows were documented during those sampling events, which may have resulted in these exceedances. Between RM 24.10 and 51.0, Ohio EPA documented lead (Pb), nickel (Ni), and zinc (Zn) metal concentrations exceeding the sediment quality guidelines (SQGs). Additionally, Ohio EPA documented total dichloro-diphenyl-trichloroethane (DDT) and total polychlorinated biphenyl (PCBs) above the SQGs and concentrations above threshold effect (TEC) between RM 26.5 and 24.10.

Ohio EPA fish sampling at RMs 26.5 and 24.1 yielded 17 to 23 native fish species of which three to five are sensitive species. Sensitive species include greenside darter (Etheostoma blenniodes), rainbow darter (Etheostoma caeruleum), smallmouth bass (Micropterus dolomieu), northern hog sucker (Hypentelium nigricans), and sand shiner (Notropis stramineus). For macroinvertebrate sampling between RM 26.5 and 24.1, the Ohio EPA documented a total of 11 and 15 Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa at these sites. Captured species are considered facultative to moderately intolerant to pollution, including sediment deposition (Ohio EPA 2023). Identified species included Baetis ssp. mayflies, Rheotanytarsus sp., and other baetids which have facultative tolerance to pollutants. Facultative to moderately intolerant species identified at both sampling locations included Hydropsychidae. The 2017-18 survey results from the downstream Gorge Dam (RM 44.5) to its confluence with Lake Erie were improved compared to previous surveys conducted in the 1980s (Ohio EPA 2023). Improvements to industrial facilities along the waterway and reducing combined sewer overflows (CSO) inputs have improved the macroinvertebrate community quality (Ohio EPA 2023).

A general fluvial geomorphology assessment of the Cuyahoga River was conducted in 1997. The river was classified using the Rosgen Classification System, which quantifies a stream’s variables or morphologic characteristics in varying levels of resolution, from broad characterizations to site-specific descriptions. The key variables used in the analysis include gradient, bankfull width and depth, sinuosity, valley confinement, and particle size. Bankfull refers to the discharge that fills a stable alluvial channel up to the elevation of the active floodplain (NPS 2004). Based on this analysis, the Cuyahoga River is generally classified as a system that has a high sensitivity to disturbance (including increases to stream flow and timing and/or sediment increases), a fair recovery potential (assumes natural recovery once cause of instability is corrected), a very high sediment supply, high streambank erosion potential, and very high vegetation controlling influence.

By combining the evaluations of QHEI, IBI, morphology assessment, and other biological indices, a well-rounded perspective of the physical and biological conditions of this reach of the Cuyahoga River can be attained. Based on the values obtained by the Ohio EPA and in comparison, to data collected during the Project’s wetland delineations in 2021 and 2022, the reach of the Cuyahoga River adjacent to the MM 20 site is anticipated to be partially- to fully-functioning in terms of chemical, physical, and biological characteristics.

Functional Assessment

Bank Erosion

Bank erosion is a natural geomorphic process or disturbance that occurs during or soon after floods. Riverbanks are transitional boundaries, or ecotones, between the aquatic and terrestrial ecosystems, and they frequently change under naturally dynamic hydrologic conditions. Bank erosion is a necessary and naturally occurring ecological process.

A natural evolving river system relies on erosional and depositional processes, which are on-going and necessary. As stewards of natural resources, the rate and scale of these processes with respect to river health, stability, and how they affect critical infrastructure influence active management decisions. The rate and scale of erosion is influenced by many factors such as local geology, soil composition and stratification, streambank angle, bank protection (organic and inorganic), rooting depth and density, streambank morphology, and hydraulic conditions.

The change or loss of any of the above variables can have cascading effects on the erosion or depositional processes exhibited in a reach. These can shift reaches to more depositional or more erosional in nature, which affects the overall balance of the sediment load for the stream. For example, often too much fine sediment in a system can lead to a loss of macroinvertebrate habitat through the filling of interstitial spaces. Conversely, freshly eroded gravels or movement of bedload deposited in the glide and head of riffles are important for spring spawning habitat for certain fish species. Thus, eliminating the supply of bank-eroded bedload material can have detrimental effects on the ecology, as well. Maintaining the appropriate balance for the system in context of the geology and watershed is ideal. Unfortunately, in today’s climate and interface between humans and waterways, many rivers and streams are subjected to an overload of sediment. The U.S. Environmental Protection Agency lists sediment as the most common pollutant in rivers and waterways. Natural erosion produces nearly 30% of the total sediment in the U.S., while accelerated erosion from human use and modifications accounts for the remaining 70% (U.S. EPA n.d.). Comment by Fish, Teresa L: I'm assuming this is supposed to be the US EPA, and not the OH EPA, since this statement appears to be copied from a previous SOF. Clarification is needed here, though, since the OH EPA is mentioned in previous sections. Comment by Jennifer Clark: Elise? Comment by Elise Bartelme: I don’t know if this is USEPA or OEPA. I did not write this. Comment by Julie Bingham: Yes it is USEPA

Ecological Functions

Banks are often characterized by bare sediment, live vegetation, or snags. In an ecological context, riverbanks are an important component of riparian zones. Ecologically functioning riparian zones provide many resources and are vital centers of biodiversity. Active channel banks form a significant ecotone between aquatic and terrestrial ecosystems with diverse natural structure and habitat functions (Florsheim et al. 2008). The main functions of riverine/riparian zones are related to fluvial hydrology and sediment dynamics, retention and cycling of nutrients and pollutants, and maintenance of habitat for fish and wildlife, including invertebrates, amphibians, reptiles, birds, and mammals (Florsheim, et al. 2008).

· Bank erosion provides a sediment source that creates riparian habitat.

· Active banks create and maintain diverse structure and habitat functions.

· Riparian vegetation promotes bank stability and contributes large woody debris.

· Bank erosion modulates changes in channel morphology and pattern.

Riverbanks accommodate highly dynamic environmental conditions. Banks can modulate floodwater surface elevations and have variable moisture regimes that satisfy the requirements of diverse plant species. Banks provide habitat at different elevation zones needed by flora and associated fauna adapted to flood pulses rising along the bank. Habitats along the bank gradient are exposed to various flood frequencies, durations, and magnitudes. Thus, plant communities closest to the channel are colonized by fast-growing, water-adapted sedges, rushes, grasses, herbs, and seedlings of shrubs and trees, whereas upland vegetation is deterred because of frequent flooding. Riverbank plant communities include trees such as cottonwood (Populus), willow (Salix), and alder (Alnus), whose roots are adapted to periodic floods (Florsheim, et al. 2008).

Streamside trees that overhang the channel are sources of organic material that provide food and cover for fish. Also, organic material from riparian vegetation is a primary food source for macroinvertebrates, including filter feeders, shredders, scrapers, and predators. Streamside trees offer shade that modifies aquatic microclimates and maintains more desirable lower water temperatures. Since the Ohio EPA defines the Cuyahoga River as a “warmwater habitat”, tree and shrub overhang provides shade and is critical to maintaining cooler water temperatures.

Three federally protected bat species are known to be in the area of the project site: the Indiana bat (Myotis sodalis), the northern long-eared bat (Myotis septentrionalis), and the tricolored bat (Perimyotis subflavus). Suitable habitat for the Indiana bat, northern long-eared bat, and tricolored bat is found within the project limits. During a special status species survey conducted on August 23-27 and September 1-3, 2021, no state or federally listed species were observed (HDR 2022b).

Overall, the quality of the aquatic habitat is ranked ‘good’ to ‘excellent’. Using the QHEI (Ohio EPA 2006), B19 scored 71.5 and assessed within the range ‘good.’ This is comparable with other studies completed along this stretch of the river by the Ohio EPA and Northeast Ohio Regional Sewer District (NEORSD). In 2017 and 2018, the Ohio EPA sampled the Cuyahoga River and 67 tributaries at 140 sites for chemical, physical, and biological monitoring. Sampling included sites within CVNP, and the Cuyahoga River was deemed in full attainment, with no listed impairments.

This stretch of the river has a designated ALU of WWH, an IBI score between 39 to 40 (indicating ‘fair’ to ‘good’ stream condition), an ICI of 34 to 50 (‘good’ to ‘exceptional’), and a QHEI of 77.75 to 82.5 (‘excellent’ range) (Ohio EPA 2023). Sites yielded 17 to 23 native fish species of which three to five are sensitive species (Ohio EPA 2023). A total of 11 and 15 Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa were reported and captured (NEORSD 2022); species considered facultative to moderately intolerant to pollution, including sediment deposition. Thus, the site has adequate fish, macroinvertebrate populations, and habitat to meet WWH criteria.

No living mussels were found at the MM 20 South project area during a September 2021 survey (MAD 2021). Only one unknown fossilized shell was found within the MM 20 South project reach.

Overall chemical water quality at RMs 26.5 and 24.1 is lower due to low DO levels and high amounts of Pb, Ni, and Zn in the sediments. Additionally, Ohio EPA found total DDT and PCBs above the SQGs and concentrations above the threshold effect. These results indicate historic contaminant inputs (e.g., DDT, PCBs) and ongoing anthropogenic inputs (e.g., nutrients) within the system. Despite this, four of the 10 Beneficial Use Impairments (BUI) listed for the Cuyahoga River have been removed. Additionally, in 2023, the Cuyahoga River sampling showed that occurrence of fish tumors and other deformities were below threshold values and therefore, the Ohio EPA announced that the Cuyahoga River now meets conditions for the removal of its BUI for fish tumors and deformities (Ohio EPA 2023).

Hydrologic Functions

Hydrologic regimes influence the relationship between upland areas and the river and changes to the river hydrology can result in geomorphic alterations and structure which will translate to changes in wetland vegetation and degradation of riverine and floodplain habitat.

The Cuyahoga River is a perennial stream with the potential for large fluctuations in water level and discharge. For example, the one-year storm interval has a discharge of 5,160 cubic feet per second (CFS) while the 100-year storm has a discharge of 17,300 CFS. These sustained flood levels are observed at USGS gage stations along the Cuyahoga River through the Park (Independence 04208000, Jaite 04206425 and Old Portage 04206000). Observations of the stage-height graphs show a typical storm peak last one to multiple days depending on the magnitude of the event. During the rise and fall of these peaks, the hydrology affects the river morphology, vegetation, and erosion/depositional patterns of the river. Comment by Fish, Teresa L: Is this number accurate? The Fitzwater WSOF states "1-year storm." Comment by Jennifer Clark: Elise: I don't see this to be the case...I see the same language in both documents. Can you cross-check that I am not missing something? Comment by Julie Bingham: The numbers are correct for the 1 and 100 year storms

Riverine Wetland Impacts

There will be a permanent impact on 1.140 acres (Cuyahoga River) and 0.150 acres of temporary impacts (Wetland B16/17/18) on riverine wetland habitat (Figure 4). Stabilization of the riverbank at MM 20 South would result in localized, direct impacts on aquatic species and habitats. The bank stabilization will impact 537 feet of riparian shoreline considered to have moderate to high functional value. The placement of rock revetment embankment fill will have permanent (see yellow polygon in Figure 4) and temporary impacts in the riverine wetland (see the red polygon in Figure 4). The total length of the riverine impact zone parallel to the riverbank measures 537 feet.

The stabilized bank will have the following adverse effects to the riverine system:

· The rock and native alluvial fill used to stabilize the eroding bank will eliminate substrate for microhabitats of plant species that would normally grow on the bank. The armoring may also impede the movement of species that use riparian zones for migration corridors, reduce structural integrity offered by roots, destroy reptile nesting areas, and diminish habitat for avifauna.

· Suspended solids contributing to the natural bedload transport system will be eliminated at this location.

· There is an opportunity for bioengineering and planting components with this alternative due to the use of rock and native alluvial soil to stabilize the bank. Allowing woody plants to grow will increase bank stability over time.

· Short-term impacts are anticipated and include destruction of aquatic organisms such as invertebrates from equipment driving in the river and increased turbidity to water quality during construction.

Wetland B16/17/18

Wetland B16/17/18 will be crossed using timber mats for construction access and will not permanently impact the wetland. Impacts can be considered temporary due to trampling and shading of vegetation; however, plants will recover once these are removed. Original access through this wetland complex was further north and required more trees to be removed. Although no wetland loss due to fill was proposed, tree removal would have caused a permanent loss of the existing palustrine forested vegetative community. Therefore, access was re-routed around the existing trees to decrease the amount of tree clearing to the smallest amount practicable while allowing large equipment to reach the Cuyahoga River. Three trees, two Salix nigra with a 3-inch DBH and one unidentifiable standing dead tree with a 24-inch DBH will be removed within the access. The portion of Wetland B16/17/18 anticipated to be temporarily impacted includes a predominance of reed canary grass (Phalaris arundinacea) and narrow-leaf cattail (Typha angustifolia) and has been assigned a Category 2 using the ORAM. Timber mats would be placed along the construction access route spanning the wetland area to minimize ground disturbance. A negligible temporary loss of wetland functions would occur due to using timber mats due to decreased exposed wetland surface area. Upon completion of construction, disturbed areas would be restored to pre-construction contours as appropriate and stabilized with a native wetland seed mix. No permanent impacts to the wetland complex W16/17/18 are proposed to occur.

Cuyahoga River (Riverine B19)

Impacts on the Cuyahoga River will involve permanent impacts. Most of the permanent impact footprint is associated with excavating the native alluvial from bar material from the opposite bank for use in stabilizing the severely eroding bank. Additional impacts include the placement of imported rock material. The imported material will consist of Ohio Department of Transportation-sized Type B and C boulder mix. This material is sized to be stable and maintain shape and placement during high flow events. The listed acreage is a “worst-case” scenario, in case the contractor needs the space; however, the project team will endeavor to keep this area minimized as much as possible. No temporary impacts to the Cuyahoga River are anticipated. Comment by Fish, Teresa L: Will there be any temporary impacts? If not, that should be mentioned. Comment by Jennifer Clark: Elise? Comment by Elise Bartelme: No temporary impacts.

Table 1 below identifies and summarizes the main geomorphic and ecological effects of channel bank infrastructure, the potential habitat or ecosystem services lost, and examples of organisms affected.

Table 1. Summary of effects on habitat of the Cuyahoga River from construction of channel bank infrastructure to control bank erosion

Geomorphic and ecological attribute

Habitat or ecosystem service influenced

Examples of organisms affected

Loss of sediment source

Grain size

Coarse-grained substrate for attachment and interstitial space for hiding from predators

Macroinvertebrates (e.g., mayflies [Ephemeroptera], caddisflies [Trichoptera], and stoneflies [Plecoptera])

Loss of geomorphic processes

Loss of bank substrate

Filter and retention of nutrients, pollutants, water quality Bank swallow (Riparia riparia) Macroinvertebrates (see above)

Natural biotic and abiotic components of land-water margin

Shoreline microhabitat: soft sediment or burrows, emergent vegetation to cling to; underwater plants, snags, roots protruding from bank

Macroinvertebrates (see above)

Roughness and irregularity in land-water margin

Variation in near-bank flow velocity, refugia during storm flows

Fish (e.g. smallmouth Bass [Micropterus dolomieu], common shiner [Luxilus cornutus], and northern hog sucker [Hypentelium nigricans] Macroinvertebrates (see above) Comment by Trimbath, Ryan J: Says see above here, there are no named fish taxa above. Below has small mouth bass. Comment by Trimbath, Ryan J: Common shiner, northern hog sucker, common shiner

Loss of woody vegetation

Bats (e.g., Indiana bat [Myotis sodalis], northern long-eared bat [Myotis septentrionalis]) and tricolored bat [Perimyotis subflavus]), birds (e.g., willow flycatcher [Empidonax traillii]), reptiles (e.g., common watersnake [Nerodia sipedon]), semiaquatic mammals (e.g., river otter [Lontra canadensis]), and macroinvertebrates Comment by Trimbath, Ryan J: add Tricolored bat (Perimyotis subflavus) more likely to occur (still fairly abundant) and forages over water, has been detected along river.

In streams where riparian woody vegetation is removed from banks and precluded from being established along erosion control structures, it follows that macroinvertebrate production, essential for aquatic food webs, is diminished and opportunity for bats to feed on the macroinvertebrates is diminished. The ecological consequences of erosion control infrastructure in urbanizing rivers include the removal of vegetation and the loss of habitat for macroinvertebrates (Florsheim et al. 2008).

Channel complexity will be reduced by the changes that the channel bank infrastructure produces, including eliminating bank irregularity and channel-width variations, homogenization of near-bank flow velocities along portions of the wall, loss of natural bank substrate, and limitation of geomorphic adjustments. (Florsheim et al. 2008).

Riverbank armoring creates two important geomorphic issues: (1) channel bank infrastructure fundamentally alters geomorphic processes, and (2) structures may be ineffective, especially over the long term. Completely arresting bank erosion will disrupt the lateral channel-bank sediment exchanges necessary to sustain many aquatic habitats (Table 1).

Bank erosion modulates changes in channel morphology and pattern. As a measure of river health, numerous studies of biological indicators identified that the current river function is good to excellent under the high sediment load. Areas disturbed by construction activities are susceptible to erosion during precipitation events. The increased sediment during construction is anticipated to have moderate and short-term impacts to the functions of the Cuyahoga River (Florsheim et al. 2008).

Cumulative Riverine Wetland Impacts from Nine Armoring Projects

Prior to 2004, 2.7 miles of the riverbank had been armored with the Park, according to the Programmatic Environmental Assessment for Riverbank Management of the Cuyahoga River (NPS 2004). By 2017, more than 6.5 miles of riverbank within the Park were armored with riprap or other material, an increase of nearly 250% since 2004 (NPS 2017). Comment by Jennifer Clark: Note for CVNP. We do not have access to this reference. If we want to keep it in can you supply the reference?

This project is being conducted in conjunction with eight additional riverbank stabilizations to armor new erosion-site reaches within the same 26-mile river valley within CVNP. To date, five of the sites have been completed and two are currently under construction. It is estimated that the nine projects will armor an additional 9,000 feet (1.7 miles) of the riverbank within this 26-mile reach (please see Figure 2). Some of the new armoring will replace the old armoring. It is highly likely that physical and ecological functions will be significantly altered with the completion of all nine armoring projects that will armor 6% of the river shoreline. Comment by Trimbath, Ryan J: Some of the eight are already complete, I think 4-5 are done and 1-2 underway as of today. Statement needs updated. Or re-worded.

A Categorical Exclusion was issued for these projects that tiered off the 2004 River Management Plan Environmental Assessment. A Programmatic Environmental Assessment (EA [NPS 2004]) was developed to evaluate the potential environmental impacts of the proposed Riverbank Management Program as compared to the existing Riverbank Stabilization Program in accordance with the requirements of the National Environmental Policy Act (NEPA), the Council on Environmental Quality (CEQ) regulations of 1978, NPS Management Policies, and NPS Director’s Order #12.

However, since the details of the structures and their impacts were not known in 2004, there have not been analyses of cumulative effects from stabilizing 1.7 miles of riverbank and of the effects on sediment transport and hydraulics. The total cubic yards of fill for the nine projects have not been calculated; and therefore, the cumulative effects of the nine projects on ecological functions, floodway processes, sediment transport, and floodplain carry capacity have yet to be analyzed. Once all nine armoring projects are in place, suspended solids that contribute to the natural bedload transport system will be reduced locally and significantly reduced along the Park’s 26-mile reach. Based on the Rosgen channel assessment performed as part of the 2004 Programmatic Environmental Assessment, the Cuyahoga River generally has a very high sediment supply. The cumulative reduction of the naturally occurring sediment load will likely have long-term adverse impacts to the river sediment bedload contribution and transport and the width to depth ratio, which will likely adversely increase the hydraulic energies throughout the system and further downstream.

Channel migration will be prevented along the 9,000 feet of bank structures. In addition, the stabilization projects include rock bendway weir features (20-foot wide and 3-foot high)…