Black Branch 2

Small headwater stream in agricultural setting with natural bedrock substrate. Low flow conditions but water is clear, suggesting reasonable base flow water quality. Adjacent agricultural land use may contribute nonpoint source nutrients and sediment during storm events.

Channel appears natural with no direct structural modifications. However, the moderate incision (3-5ft banks) and exposed bedrock substrate suggest some downcutting, possibly related to altered hydrology from adjacent agricultural land use changes. The channel is moderately entrenched but appears to have achieved a degree of stability on bedrock.

Moderate channel incision (3-5ft bank heights) reduces floodplain access. The bedrock-controlled channel limits further downcutting but the stream is clearly disconnected from its floodplain for most flow events. Agricultural land use in the watershed likely contributes to flashier hydrology.

Very little sediment deposition visible. The bedrock substrate is largely clean with minimal fine sediment accumulation. The bedrock-dominated channel has high sediment transport capacity that keeps the bed relatively clear. Some minor accumulation in pool margins.

Under current low flow conditions, only slow-shallow runs over bedrock and slow-deep pools are visible. No fast-deep or fast-shallow regimes apparent. At higher flows, more diversity would likely exist, but current conditions show limited velocity-depth variability.

Water fills approximately 25-50% of the channel width. Large areas of bedrock substrate are exposed, especially along the margins and between pools. Low flow conditions prevail with water confined to the lowest thalweg and pools.

The bedrock channel creates some natural riffle-like features where the bed elevation changes, but under low flow conditions these are subdued. The natural bedrock steps create moderate habitat diversity. Pools are interspersed but riffle development is limited by the flat bedrock surface.

This is a bedrock-controlled headwater stream typical of the Middle Tennessee limestone/shale geology. The B-type classification reflects moderate entrenchment, riffle-pool morphology on bedrock, and moderate gradient. The bedrock substrate prevents further downcutting but lateral erosion is occurring on the outer bank. The channel appears to have achieved a degree of dynamic equilibrium with the bedrock acting as grade control. This could also be classified as a Bc (bedrock-influenced) type.

The left bank (viewed in the LEFT face/right side looking downstream) shows moderate height (3-5ft) with some root exposure but generally vegetated to the bank top. Moderate stability provided by tree and shrub roots, but evidence of scour and some bare soil at the bank face. Bank toe has some bedrock exposure providing natural armor.

Approximately 60-75% vegetation coverage on the left bank. Dense shrub and vine tangles at the top, but bank face shows patches of bare soil. Some invasive species suspected in the understory. Root systems provide partial protection. Currently bare canopy reduces protection from rain splash.

Left bank has narrow riparian buffer with agricultural field visible beyond. Bank height moderate at 3-5 feet. Natural bedrock at base provides some resistance to erosion. Vine and shrub growth moderate but appears to include invasive species.

The right bank (viewed in the RIGHT face) shows steeper angle with more exposed soil and active erosion. Bank height 3-5ft with undercutting evident. Exposed root systems indicate active bank retreat. Less than 33% of eroding face protected by roots at baseflow elevation.

Approximately 50-65% coverage on bank face. Upper bank has vine and shrub cover, but lower bank face is exposed with significant bare soil. Root exposure moderate to severe indicating bank retreat. Agricultural field visible beyond narrow buffer suggests limited vegetation depth.

Right bank shows more active erosion than left bank. Steep face with undercutting, exposed roots, and bare soil. Narrow riparian buffer with agricultural land beyond. This bank appears to be on the outside of a slight meander, contributing to higher erosion rates.

Through the bare canopy, open agricultural/pasture land is visible approximately 25-50 feet from the channel. This represents roughly 3-5x the channel width for this narrow stream, but the overall buffer is still relatively narrow. The buffer appears to be a single row of trees with understory shrubs.

Similar to left bank, agricultural land visible through bare trees approximately 25-50 feet from channel. Narrow but continuous buffer strip of deciduous trees and shrubs.

Trees and shrubs present along banks but the riparian zone is narrow with agricultural land encroaching. Vegetation is somewhat disturbed and includes likely invasive species. The buffer provides some function but is compromised by limited width and agricultural adjacency.

Currently minimal shade due to bare deciduous canopy in early spring. When fully leafed out in summer, canopy coverage would likely be 50-75% based on the moderate tree density overhead. The current bare canopy provides essentially no shade. Score reflects the expected summer conditions based on tree density visible in the UP face.

Both banks meet minimum 30ft buffer. Agricultural land immediately adjacent to narrow buffer on both sides presents opportunity for buffer widening. Current buffer width marginal for adequate filtering of agricultural runoff.

Bedrock-dominated substrate provides limited colonization habitat. Some undercut banks and exposed root systems provide favorable substrate. A few loose rocks and cobble-sized pieces along margins offer some colonization surfaces, but the dominant smooth bedrock is relatively poor for epifaunal colonization. Approximately 20-35% of substrate is favorable.

Where loose rock and cobble are present in the channel, they show moderate fine sediment surrounding them (approximately 25-40%). The dominant bedrock substrate is clean. Assessment is somewhat limited by the bedrock-dominated nature of this reach — embeddedness is more applicable to gravel/cobble reaches.

Shallow pools visible in the bedrock channel where natural depressions hold water. Pools are small and shallow, likely less than 1-2 feet deep even at normal flow. Pool bottom is visible due to shallow depth and clear water. Limited pool habitat under current low flow conditions.

Limited fish cover with only 3 types identified: undercut banks along the eroded right bank, exposed root mats, and some woody debris. The bedrock channel lacks boulders, deep pools, overhanging vegetation (currently bare), and macrophyte beds. Small stream size limits overall fish cover potential.

No artificial barriers visible within the reach. However, the very low flow conditions during dry periods could seasonally limit fish movement through shallow bedrock runs. No culverts, dams, or weirs visible.

Sparse LWD in the visible reach. The down face shows some woody debris and exposed roots, and a few small branches visible in channel in the front and back views. No debris jams or large pieces. The narrow channel and moderate canopy provide some LWD recruitment potential, but current levels are low.

Three habitat types identified: undercut banks providing shelter, some coarse gravel/cobble fragments along bedrock margins, and leaf packs accumulating in pool edges. The dominant bedrock provides limited attachment surfaces for many macroinvertebrate taxa. Woody debris is sparse. Habitat diversity is limited by the bedrock-dominated substrate.

Habitat conditions suggest potential for moderate macroinvertebrate community. Clean bedrock with some crevices, leaf packs, and undercut banks provide habitat. Clear water indicates acceptable water quality. Score of 6 reflects habitat-based estimate for a Group II community.

No macroinvertebrates directly observed from imagery. Score based on habitat assessment — the bedrock substrate with some cobble, undercut banks, and clean water suggests potential for Group II (facultative) communities. The natural bedrock substrate and clear water support a moderate score. Actual sampling would be needed to confirm.

Suitable Habitat: No

Small headwater stream with limited habitat complexity. Bedrock substrate and low flow limit potential for rare aquatic species. The narrow riparian corridor provides some terrestrial wildlife habitat but is limited by agricultural adjacency.

No wildlife directly observed. Early spring timing and surveyor presence may have displaced mobile species. The stream provides some habitat features including undercut banks, brush piles from vine tangles, and bedrock shelter. Low flow conditions limit fish habitat.

Water is clear with good visibility to the bottom throughout the visible reach. No discoloration, sheen, or foam observed. The clear water and clean bedrock surface suggest good baseflow water quality. Slight brown tint in pools may be natural tannins from leaf litter. Score reduced slightly from optimal because the shallow depth makes full clarity assessment difficult.

Very little algal growth visible on bedrock surfaces. No macrophytes observed. Water is clear with no green tint. Some minor biofilm on rock surfaces is normal. The bedrock substrate and high canopy cover (when leafed out) likely limit algal growth. Adjacent agricultural land could contribute nutrients during runoff events.

No direct evidence of manure or waste in the stream. No livestock access points visible. However, agricultural/pasture land visible on both sides of the narrow buffer could include livestock operations. No fencing visible to prevent potential livestock access. Score slightly below optimal due to proximity to agricultural land.

Currently early spring with bare canopy providing minimal shade. When fully leafed out, the deciduous canopy along this narrow corridor would provide moderate to good shade coverage. The narrow riparian buffer on both sides limits the effectiveness of shading, particularly during midday. Bedrock substrate absorbs and retains heat. No urban thermal impacts apparent in this rural setting. Agricultural land use does not contribute significant thermal loading. Deepening of pools would enhance thermal refugia.

No permit compliance concerns identified at this location.

Terrestrial Invasives Assessment

Aquatic Invasives Assessment

Confidence in invasive identification is low due to bare/dormant vegetation in early spring. Dense vine tangles on both banks appear consistent with Japanese honeysuckle, which is extremely common in Middle Tennessee riparian corridors. Some shrub growth patterns suggest possible bush honeysuckle or privet. Full growing-season survey recommended for accurate invasive species inventory.