Streams in the southeast portion of this subbasin has been completely channelized and leveed. Aquatic habitat problems include unstable streambed substrates, loss of deep water habitat, and lack of riparian corridor.
In the western and northern portions of the subbasin, no major channelization projects have occurred. Small channelization projects, gravel pushing, and poor gravel removal methods are widespread and relatively common. The detrimental effects of these activities on the stream health are significant, but localized. It is difficult to quantify the cumulative effects on the streams.
Instream gravel mining formed both the Hendrickson and the Keener Springs pools in the Black River (mining has since ceased). The expected bank failures upstream of these pools due to headcuts have not occurred. However, local residents indicate that the Keener Springs pool is rapidly filling in with gravel.
No large channelization projects have occurred. As in the lower subbasin, small channelization projects, gravel pushing, and poor gravel removal methods are relatively common.
Stream Habitat Assessments
The MDC Stream Habitat Assessment Device (SHAD) was used to describe the quality of streambank, corridor, and channel habitat conditions in the basin. SHAD uses objective measurements and subjective ratings to rank particular habitat parameters into categories. Forty-five and 29SHADs were conducted in the lower and upper subbasins, respectively.
Excluding the Lowland ditches, the majority (62-92%) of the riparian corridors surveyed were classified as "good" (Table Hc01). Only 4% of the corridors on the ditches were rated "good".
Excluding the Lowland ditches, the riparian corridor averaged 60 -75 feet. Along the lowland ditches, the riparian corridor averaged only 11 feet.
Streambank erosion is not a major problem in this subbasin. Only 1% of the 8.5 miles of stream surveyed had severe erosion problems (Table Hc02). The streambank erosion problems which were noted, were all associated with missing riparian corridors. Severe bank erosion is not occurring on the lowland ditches because of soil composition and low stream gradients (~1ft/mile). However, instream woody habitat is completely missing from most ditches.
Of the approximately 18 miles of riparian corridors surveyed, 50-100% were classified as "good" (Table Hc01). Only 0-12% of the riparian corridors were classified as "poor. The average riparian corridor range was 58-100 feet (Table Hc01). However, some streams that were not part of the survey, such as the North Fork of Webb Creek, Doe Run Creek, and Dickson Valley Creek have several miles of corridor that are nonexistent or consists of one row of trees.
While few severely eroding streambanks were noted (Table Hc02), many streambanks were classified as "moderately eroding". Many streams, such as the Black River, are experiencing moderate erosion even with an excellent riparian corridor. This erosion can be attributed to the excessive amounts of gravel bedload in the stream channel. Almost all SHAD surveys had comments regarding large amounts of unconsolidated gravel in the stream channel.
Stream Improvement Projects
As in most river basins, there have been a variety of unsuccessful attempts by private landowners to stabilize streambanks. These attempts include channelization, hard points, bank armoring using a variety of materials including rock, gravel, car bodies, and construction debris. MDC personnel have not installed any improvement projects (e.g., cedar tree revetments) in either subbasin.
The state's terrestrial natural resources have been classified into six major categories" Forest, Savanna, Prairie, Primary, Wetland, and Cave communities. These communities have been further divided based on characteristic features such as topography, size, distribution, and characteristic plants (Nelson 1987). The Missouri Department of Conservation's Natural Heritage Program (NHP) has identified 64 high-quality communities in the Black River basin (Table Hc03).
Seventeen high-quality natural communities, representing Forest, Savanna, and Wetland categories, have been identified (Table Hc03). In the Forest category, Dry-Mesic Igneous Forest, Wet Bottomland Forest, and Wet-Mesic Bottomland Forest are present. The only high-quality Savanna community identified is a 60-acre igneous savanna. The Wetland category is represented by Deep Muck Fen, Forested Acid Seep, Forested Fen, Oxbows and Sloughs, Pond Shrub Swamp, and Swamp communities.
The NHP has identified 47 high-quality natural communities (Table Hc03). This subbasin contains both upland and bottomland forest. The upland forest habitats include Dry-Mesic Forest, Mesic Limestone/Dolomite Forest, Dry Igneous Forest, Dry Mesic Igneous Forest, and Mesic Igneous Forest. The bottomland forest type is the Dry-Mesic Bottomland Forest. The Primary communities include the Dry Limestone/Dolomite Cliff, Dolomite Glade, and Igneous Glade. Five Wetland community types (Acid Seep, Deep Muck Fen, Prairie Fen, Forested Fen, and Pond Shrub Swamp) are also present. There is only one Cave community type identified, the Effluent Cave.