Black Branch 2

Small headwater stream in agricultural landscape. Evidence of channel incision, bank erosion, and limited riparian buffer suggest habitat degradation. Substrate dominated by flat limestone gravel with fine sediment infilling. Low flow conditions during assessment period.

Channel appears natural without direct structural modifications, but shows evidence of incision and active bank erosion including undercutting and tree falls. The narrow, incised character suggests hydrologic alteration from surrounding agricultural land use changes rather than direct channel modification. Score of 5 reflects moderate downcutting without direct engineering alterations.

Channel shows moderate incision with banks 3-6 feet above the stream bed. Agricultural land use changes in the watershed have likely increased peak flows and contributed to channel downcutting. The stream appears moderately disconnected from its floodplain. Flooding of adjacent agricultural fields is likely infrequent.

Some fine sediment deposition visible between limestone cobbles and gravel. Channel bed appears relatively stable with natural limestone substrate exposed. Fine sediment fills approximately 20-30% of interstitial spaces. No major bar formations visible but fine sediment infilling is evident.

At current low flow conditions, the channel is dominated by slow-shallow and fast-shallow regimes. No deep pools or fast-deep areas visible. The uniformly shallow conditions limit habitat diversity. During higher flows, additional regimes would likely be present.

Water fills approximately 25-50% of the channel width. Extensive exposed substrate is visible on both sides of the narrow flow path. The active wetted width is significantly less than the bankfull width, indicating low flow conditions.

The visible reach appears dominated by uniform shallow runs over flat limestone substrate. Some slight riffle texture is visible where flow crosses rock ledges but distinct riffle-pool sequences are not well developed. The flat limestone substrate does not create well-defined riffle formations.

This appears to be an F-type stream - entrenched with moderate sinuosity and active bank erosion. The channel has incised through what may have been historically wider floodplain surface now converted to agriculture. The flat limestone substrate is characteristic of Central Tennessee streams in the Nashville Basin. Active bank erosion with mass failures (fallen trees) is consistent with Rosgen F-type instability. The stream may be in a state of degradation or widening within its incised trench.

Left bank (facing downstream) shows moderate instability with steep slopes, exposed soil, and evidence of active erosion. Some tree root systems provide localized stability but coverage is inconsistent. The narrow riparian buffer transitioning to agricultural fields provides limited long-term stabilization. Bank height is moderate at 3-6 feet.

Vegetative cover on the left bank is approximately 50-65%. Bare winter conditions reduce apparent coverage, but even accounting for dormancy, the sparse tree spacing and narrow buffer width leave significant bare areas. Some areas show active erosion with exposed soil. Eastern red cedars provide year-round coverage but deciduous trees are bare.

Left bank transitions quickly from stream to agricultural field with a narrow riparian corridor of 10-30 feet. Active erosion is visible at the bank toe. Some trees showing root exposure. The narrow buffer is insufficient for long-term bank stability given the agricultural land use.

Right bank shows moderately unstable conditions with steep slopes and evidence of active mass failure including at least one large fallen tree with exposed root wad visible in the upstream view. Undercutting is evident. Dense vegetation on the slope provides some stability but active erosion processes are ongoing.

Right bank has denser vegetation than the left, with approximately 65-75% coverage in winter dormancy. Dense understory shrubs and tangled vines provide some root stabilization. However, the steep bank angle and evidence of tree falls indicate that vegetative protection is being overwhelmed by erosive forces.

Right bank shows more severe erosion than left bank, with evidence of mass wasting including fallen trees with exposed root systems. The bank is steeper and taller on this side, suggesting the stream is actively migrating laterally. Dense understory vegetation provides some resistance but is being undermined.

Left riparian buffer is narrow, estimated at 10-25 feet before transitioning to open agricultural field. For a channel approximately 5-8 feet wide, this represents approximately 2-3x channel width, but the narrow absolute width is concerning for buffer function. Agricultural fields are clearly visible through the thin tree line.

Right riparian zone appears wider than the left, with dense vegetation extending further from the channel. The steep slope with dense understory and trees provides a buffer of approximately 50-100 feet based on the visible extent in the right bank view before transitioning to what appears to be additional vegetation or agricultural land beyond.

The floodplain vegetation is marginal. The left side has been converted to agriculture with only a narrow strip of trees remaining. The right side retains more natural vegetation but the stream is incised and disconnected from its floodplain. The overall riparian-floodplain ecosystem is not functioning in a natural state due to agricultural conversion and channel incision.

During winter dormancy, canopy cover is approximately 25-40% from bare deciduous branches and scattered Eastern red cedars. During growing season, coverage would increase to approximately 50-70% based on branch density observed in the upward view. The narrow buffer on the left side limits full canopy coverage over the channel.

Left bank buffer is non-compliant with TDEC MS4 permit section 4.2.5.4 minimum 30ft riparian buffer requirement. Agricultural field cultivation extends to within approximately 10-25 feet of the stream bank. Buffer restoration on the left bank should be a priority. The right bank buffer appears to meet minimum requirements.

Approximately 25-35% of visible substrate is favorable for epifaunal colonization. The flat limestone pieces provide some surface area but are prone to scour. Root wads from fallen trees and undercut banks provide localized favorable substrate. The lack of diverse substrate sizes and dominance of flat limestone limits colonization potential.

Flat limestone pieces are approximately 25-50% embedded in fine sediment. The down view shows fine material filling gaps between rock pieces. Some interstitial spaces remain open but sedimentation is reducing habitat quality in the substrate.

Pools are essentially absent in the visible reach. The channel is uniformly shallow with the entire bottom discernible. A small plunge area may exist near the fallen tree upstream, but no significant pool habitat is evident. The flat limestone substrate does not create natural pool formations.

Three types of fish cover are present: woody debris from fallen trees, undercut banks, and root mats from exposed tree roots. Deep pools, boulders, macrophyte beds, and backwater pools are absent. The limited cover types restrict fish habitat quality.

No artificial barriers to fish movement visible in this reach. However, the very low flow conditions may seasonally limit fish passage through shallow riffles. The fallen tree may create a minor obstruction but does not appear to fully block the channel.

Sparse LWD is present, estimated at 3-7 pieces per 100m. One large fallen tree with root wad is prominently visible spanning near the channel in the upstream view. Some smaller woody debris is scattered. The LWD is primarily from recent bank failure rather than natural recruitment. No debris jams formed.

Three types of invertebrate habitat are present: coarse gravel/limestone substrate, submerged logs from fallen trees, and undercut banks. Leaf packs and fine woody debris are limited. The flat limestone substrate provides some colonization surfaces but lacks the diversity of cobble and boulder habitat. Winter conditions limit assessment of leaf pack availability.

Score assigned based on habitat conditions rather than direct observation. The moderate water quality, available substrate types, and presence of some cover features suggest the stream could support a facultative community. However, low flow, limited pool habitat, and fine sediment infilling may reduce diversity.

No macroinvertebrates directly observed from imagery. Score based on habitat assessment only - habitat conditions suggest Group II facultative organisms would likely dominate based on substrate type, moderate water quality, and available habitat features. Actual sampling would be needed to confirm.

Suitable Habitat: No

The degraded habitat conditions, incised channel, and limited pool habitat reduce the likelihood of supporting sensitive species. However, the limestone substrate in Central Tennessee can support diverse aquatic communities when habitat conditions are adequate.

No wildlife directly observed during the survey. Winter conditions and human disturbance from the surveyor's presence may have suppressed visible wildlife activity. The reach provides limited habitat for fish due to very shallow flow and lack of pools. Brush piles and rock accumulations provide potential small mammal and reptile cover.

Water has a slight brown tint but is relatively clear at current low flow. The brown coloration may be from tannins or slight turbidity. Objects are visible through the shallow water. No sheen, film, or abnormal conditions observed. Score of 6 reflects slightly impaired clarity with natural brown coloration.

Minimal algae growth is visible on substrate in the visible reach. No macrophytes observed, which may be partly due to winter dormancy. Water is not green-tinted. Adjacent agricultural land could contribute nutrients but no excessive enrichment signs are apparent at this location.

No direct evidence of manure or livestock waste in the stream or on banks. The adjacent agricultural fields appear to be cropland rather than pasture, with no evidence of livestock access. However, the proximity of agricultural operations suggests potential for nutrient and sediment runoff.

Winter assessment limits thermal evaluation. The narrow left bank buffer and bare canopy conditions in winter provide minimal shading. During growing season, shade would increase but the narrow buffer on the left side would still leave portions of the channel exposed to direct sunlight. No groundwater seeps or springs observed. Agricultural runoff during summer could contribute warm water inputs.

The narrow left bank riparian buffer (less than 30 feet) adjacent to agricultural fields may not meet TDEC MS4 buffer requirements. Agricultural activities appear to extend close to the stream bank. Ongoing bank erosion and mass failure suggest the stream is responding to watershed-level hydrologic changes from agricultural land use.

Terrestrial Invasives Assessment

Aquatic Invasives Assessment

Low confidence identification due to winter dormancy. The dense tangled understory on the right bank includes vines and shrubs that may include bush honeysuckle and Japanese honeysuckle based on growth form and density patterns typical of these species in Central Tennessee. Positive identification would require growing season assessment. The dense vine tangles visible in several views are suggestive of honeysuckle but cannot be confirmed without leaves.