Black Branch 2

Small headwater stream in rural agricultural setting. Bedrock-controlled channel with low flow. Stream appears functional for its size class but limited habitat diversity due to bedrock dominance and very shallow flow.

Channel appears natural with no evidence of straightening, riprap, or other structural alteration. The bedrock-controlled channel limits downcutting. Some minor lateral erosion at bank edges but overall the channel form is natural. Score reduced slightly from 10 because the adjacent pasture land use may have historically influenced the channel corridor, and some minor bank scour is evident.

Channel is bedrock-controlled with very low banks, suggesting good floodplain connectivity. The flat pasture on the right bank likely receives flood waters during higher flows. No incision evident - bedrock prevents downcutting. Minor score reduction due to upstream agricultural land use potentially altering hydrology with faster runoff from maintained pasture.

Bedrock-dominated substrate shows minimal sediment deposition. The bedrock is largely exposed with very little accumulated fine sediment. Some thin mud/silt wash over the bedrock but no significant bar formation. The bedrock control limits deposition potential.

At current low flow, the stream is almost entirely shallow. The bedrock bed creates some variation between slower pooled areas and faster sheet flow sections, but no deep water is evident anywhere. Only slow-shallow and fast-shallow regimes present.

Water is present throughout the visible channel but is very shallow - essentially sheet flow over bedrock. The water appears to fill approximately 50-75% of the channel width, with some exposed bedrock edges. The flow is continuous but minimal in depth.

The bedrock channel creates some natural variation where water flows over ledges and breaks, but the overall gradient is low and the flow is predominantly uniform sheet flow. Some small breaks in the bedrock create micro-riffles but they are not well-defined. The bedrock steps visible in the front view provide some riffle-like habitat.

This is a small bedrock-controlled headwater stream in what appears to be the Nashville Basin limestone region. The flat limestone bedrock controls the channel grade and prevents incision. The channel form is somewhat between B and E types but the bedrock control makes Rosgen classification less informative. The wide-shallow morphology at low flow and bedrock bed are the dominant features. Low confidence in classification because bedrock-controlled streams do not fit neatly into the Rosgen system.

Left bank is low (under 3 feet) which is favorable. However, the bank has areas of bare soil and some scour/undercutting visible in the back view. Grass and herbaceous cover provide some root protection but trees are set back from the immediate bank edge in many locations. The dormant herbaceous cover and mixed shrub vegetation provides moderate protection. Bedrock at the bank toe provides some natural stability.

Left bank has moderate vegetation coverage. The immediate riparian zone has a mix of dormant herbaceous plants, some shrubs, and scattered trees. The dormant season reveals some gaps in coverage. The denser shrub/tree thicket visible in the left view provides a reasonable buffer, but the immediate bank edge shows some bare soil patches and sparse grass cover. Estimated 65-75% coverage.

Left bank has better riparian buffer than right bank with denser shrub/tree cover extending away from the channel. Some yucca plants present which may indicate old homestead site. Minor erosion at bank-channel interface.

Right bank is low which is favorable, but the mowed pasture extends very close to the channel edge with minimal riparian buffer. Grass roots provide some bank stability but the lack of woody root structure makes the bank more vulnerable. Some minor scour visible at the bank edge. The bedrock provides natural toe protection.

Right bank is dominated by mowed grass/pasture extending to the channel edge. While grass coverage is high, the vegetation type provides minimal bank protection compared to woody vegetation. Only scattered trees near the channel with most woody vegetation set back. The grass is short/mowed which reduces its filtering and stabilization capacity. Estimated 60-70% effective vegetative protection when considering quality of protection, not just coverage.

Right bank has minimal riparian buffer - mowed pasture extends to channel edge. Scattered mature trees provide some shade but insufficient woody root structure for bank protection. This is the more compromised bank in terms of riparian function.

Left bank has a moderate buffer of shrubs, small trees, and herbaceous vegetation extending approximately 25-50 feet from the channel before transitioning to more open conditions. For a 3-5 foot wide channel, this represents several times the channel width. The vegetation is naturally regenerating with dormant herbaceous cover, shrubs, and scattered mature trees.

Right bank has virtually no riparian buffer. Mowed pasture extends nearly to the channel edge with only scattered trees providing any woody riparian function. The effective natural buffer width is less than 10 feet in most locations visible. This is severely compromised for a stream buffer.

The floodplain vegetation is in a marginal state. The right bank floodplain is entirely converted to maintained pasture/lawn. The left bank has some natural regeneration of shrubs and trees but is still relatively sparse and young. Overall, the floodplain vegetation is not in a natural state - it has been significantly altered by agricultural use.

Currently in winter with bare deciduous trees, shade is minimal (<25%). During summer leaf-out, the scattered trees along the corridor would provide perhaps 25-50% shade over the narrow channel. The narrow channel width means that even scattered trees can provide moderate shade when in leaf. Current winter condition is unshaded but this would improve significantly in growing season. Score reflects estimated annual average condition.

The right bank has severe buffer deficiency with mowed pasture/lawn extending to the channel edge. This is a significant deviation from TDEC MS4 permit section 4.2.5.4 requirements. Buffer restoration on the right bank would be highly beneficial and feasible given the flat terrain and available area. Left bank buffer is marginally adequate.

The bedrock-dominated substrate provides very limited colonization habitat for epifaunal organisms. Bedrock is relatively smooth with few crevices visible. There is minimal woody debris, very few cobbles or boulders (bedrock surface is relatively uniform), and limited undercut bank habitat. Perhaps 20-30% of the visible substrate offers favorable conditions, primarily at bedrock ledge edges and the few undercut bank areas.

Using low gradient criteria as this is a low-gradient bedrock stream. The bed is dominated by bedrock with very little loose substrate. While bedrock itself scores low on diversity, the thin sediment veneer over bedrock and some loose rock fragments at bedrock ledge edges provide moderate conditions. Score reflects the bedrock dominance which limits substrate diversity but does not have the sediment burial issues typical of degraded streams.

The stream is extremely shallow with bedrock bed exposed throughout. No discernible pools are visible in any direction. The water depth appears to be only 1-3 inches over the bedrock surface everywhere visible. The entire bed is discernible. Some very minor depressions in the bedrock may hold slightly deeper water but no functional pools exist at current flow.

Very limited fish cover. The only cover types identifiable are some minor undercut banks and overhanging vegetation (grass/herbs at bank edge). There are no logs/woody debris in the channel, no deep pools, minimal boulders, no macrophyte beds, no backwater pools. The stream at this location is too shallow to support most fish species, and cover is extremely limited.

No barriers to fish movement are visible within the reach. However, the very shallow flow during low-flow periods would itself create a seasonal barrier for fish movement. The bedrock ledges visible create small steps that could impede movement at very low flows. Score of 8 reflects potential seasonal low-flow limitation.

No large woody debris is visible in the channel in any direction. The channel appears completely devoid of LWD. This is likely due to the very small channel size and possible historic clearing of woody vegetation from the corridor, particularly on the right bank pasture side. The lack of LWD significantly limits habitat complexity.

Limited macroinvertebrate habitat diversity. The bedrock bed provides minimal interstitial habitat. Some minor undercut bank areas and scattered loose rock fragments at bedrock ledge edges provide the only habitat types. No leaf packs, logs, fine woody debris, cobble fields, or other habitat types visible. The smooth bedrock surface and very shallow flow severely limit habitat complexity for invertebrate colonization.

Habitat-based estimate. No organisms directly visible in the imagery. The clean bedrock substrate with flowing water could support some facultative organisms. The rural agricultural setting without obvious pollution sources suggests moderate biological conditions are possible, but limited habitat diversity would constrain diversity. Conservative score assigned.

No actual macroinvertebrates observed in imagery - assessment is based on habitat quality only. The bedrock substrate with some undercut banks could support Group II facultative taxa. Score of 6 is a habitat-based estimate assuming moderate conditions in this small rural headwater stream.

Suitable Habitat: No

The stream is too small and shallow to support significant fishery resources. Bedrock-controlled headwater streams in central Tennessee can support some specialized invertebrate communities but habitat at this location is limited. The rural agricultural setting without heavy pollution provides reasonable water quality conditions but habitat limitations reduce biodiversity potential.

No wildlife directly observed. Winter conditions and the presence of a survey technician in the channel may have temporarily displaced any fauna. The stream corridor provides some wildlife movement habitat connecting the left bank shrub/tree corridor. The narrow channel and shallow water limit aquatic wildlife potential.

Water is slightly turbid with a brownish tint, which is partially attributable to the limestone bedrock color showing through the very shallow water. The water does not appear heavily turbid but is not crystal clear either. No oil sheen, foam, or other contamination indicators visible. Depth is too shallow to properly assess clarity depth. Score reflects slightly brownish water that may be influenced by minor sediment or natural bedrock coloration.

Water does not show green coloration or excessive algal growth. The winter season limits assessment but there is no evidence of heavy nutrient loading such as algal mats or thick periphyton on the bedrock. Some minor biological film appears on the bedrock surfaces but this is normal. No macrophytes visible. The adjacent pasture could contribute nutrients via runoff, especially on the unbuffered right bank, but current conditions don't show enrichment impacts.

No manure or waste is visible in the stream or on the banks. The mowed pasture on the right bank could support livestock, but no animals are visible and no manure, hoof prints, or livestock access trails are evident. Fencing visible in the right bank view may serve to restrict livestock access. Score of 7 rather than 10 because the pastoral land use creates potential for livestock-related impacts even if not currently observed.

Currently in winter with minimal shade due to bare deciduous canopy. During summer, scattered trees along the corridor would provide intermittent shade but significant portions of the channel, especially along the right bank with mowed pasture, would be fully exposed to solar radiation. The very shallow water depth makes this stream particularly vulnerable to thermal stress during summer months. Establishing a riparian buffer on the right bank would significantly improve shade conditions. No impervious surfaces nearby, so thermal pollution from stormwater runoff is not a concern at this rural location.

No active permit violations observed. The lack of riparian buffer on the right bank is a management concern but not necessarily a permit violation at a rural agricultural site.

Terrestrial Invasives Assessment

Aquatic Invasives Assessment

Other Invasive Species

Winter dormancy makes positive identification of most invasive species difficult. Some of the dense shrub growth on the left bank and in hedgerows could include bush honeysuckle based on growth form, but confident identification requires leaf-on conditions. Japanese honeysuckle vine may be present in the tangled understory. Yucca plants visible on the left bank near the channel are non-native ornamentals suggesting a former homestead or intentional planting. Overall invasive pressure appears low but should be reassessed during growing season.