According to the Missouri Water Atlas (1986), the main stem Bourbeuse River has no channelized segments in its 147 stream miles, nor are any major segments impounded. Some tributaries such as Brush Creek with Indian Lake and the upper Bourbeuse River with Towell Lake (see Hydrology Section, Dam and Hydropower Influences) are impounded. Also, Noser Mill near Highway 185 and Goodes Mill below Highway 50 have dams that behave as grade controls. Similarly, an untold number of bridges and fords on secondary streams can change stream gradient on smaller order tributaries, and in general, alter discharge rates.
Dredging, Gravel Mining
In-channel mining has the potential to artificially accelerate a stream’s natural geomorphic processes by increasing channel slope, channel water velocity, and sedimentation. A stable stream is in dynamic equilibrium. A section of stream gravel removed from a location, resulting in stream disequilibrium, will cause erosion upstream from the nick-point (removal area) and within the nick-point. As the stream seeks new mass-balance equilibrium, a nick-point will eventually erode away and migrate upstream in a process known as "head-cutting" (Patrick et al. 1993). In an effort to control erosion, landowners sometimes resort to "channel reaming," a process of plowing out a straight and uniform new channel in the stream bed or gravel bar, followed by blocking off the old channel with gravel or debris, and often accompanied by pushing loose gravel against eroded banks. The Bourbeuse River and its tributaries have segments altered by these detrimental activities (see Land Use Section, Mining).
Natural Features Inventory
The Missouri Natural Features Inventory is completed for Franklin (Kurz 1981), Phelps (Ryan 1992), Gasconade, and Maries (Currier 1991), and Crawford (Ryan 1993) counties. The objective of the MDC statewide Natural Features Inventory was to locate, describe, classify, and rank high quality elements of Missouri's natural habitat. With this knowledge, Missourians protect the state’s outstanding features through inclusion to the state natural-areas system by voluntary landowner agreements or by providing informed management decisions in ecologically sensitive areas already in public ownership.
Identifying sites within the Bourbeuse River watershed and adjacent areas involved surveying seven categories:
•natural communities (undisturbe assemblages of plants and animals),
•state-listed species habitats (rare and endangered species),
•habitats of relict species,
•outstanding geologic features,
•areas for nature studies,
•other unique features,and aquatic communities.
The natural community, geologic feature, and aquatic community sites were further classified using the Terrestrial Natural Communities of Missouri (Nelson 1987) and the Geologic Natural Feature Classification System for Missouri (Hebrank 1989). Following the classification, biologists graded sites for their natural quality, and ranked them to provide a means of comparing similar features for their preservation value (Ryan 1993; Currier 1991). Rankings were in three categories: significant, exceptional, or notable (Ryan 1993; Currier 1991). According to Ryan (1993), areas that he defined as significant natural features should receive a form of protection (possible inclusion in the Missouri natural areas system), and areas that he defined as exceptional are not of natural area quality but deserving of some protection. Lastly, notable areas on private land do not merit special management or protection. Kurz (1981) ranked the potential natural features sites differently. Areas were either special natural features or notable.
In Gasconade County, several upland forest types were identified as rare Dry-Mesic Limestone/Dolomite Forests (T41N, R6W, Sec. 1, 2; T40N, R5W, Sec. 6, 7) near the Mint Spring Area of Gasconade County (Currier 1991). Mint Spring, designated a Missouri Natural Area in 1982, has an acid seep (T40N, R6W, Sec. 13), a forested acid seep (T40N, R6W, Sec. 13), and a mesic bottomland forest with a natural Ozark headwater stream. In Maries County, a 0.5-acre pond swamp (called Ash Pond, T40N, R7W, Sec. 22) has an unusual community association, dominated by green ash, buttonbush, and sedges. An intermittent slough in a young to mature bottomland forest along the Bourbeuse River (T34N, R7W, Sec. 23, 24) was identified as potential wetland. Finally, Gasconade County, besides several other counties, has glades that are worthy of protection. These glades are usually dry south-facing slopes with unique wild flowers and grasses, prickly pear cacti, few trees, and numerous lizards.
Franklin County is the third largest county in the state. Kurz (1981) noted that most of the county has been cleared and plowed or grazed, leaving only the northern- and southern-extreme part of the county having the natural features. Several of the sites visited by Kurz included the areas within the Meramec River watershed. In the Bourbeuse River watershed portion of Franklin County, several small streams such as the large portions of the Little Bourbeuse River were notable natural systems (Kurz 1981). This notable portion of the Little Bourbeuse River began with T41N, R4W, Sec. 26 and extended into Crawford County. In the Crawford County survey, Ryan (1992) noted the unique sandstone and shale geological features of Little Bourbeuse River watershed (T40N, R4W, Sec. 13, 35), near Argo. Large portions of the Bourbeuse River near Strain (T42N, R4W, Sec. 27) thru Noser Mill (T42N, R2W, Sec. 28 thru Sec. 2) to Union (T43N, R1W, Sec. 26) were noted by Kurz as an outstanding example of an Ozark border stream. Kurz (1981), also noted the outstanding example of Kratz Spring (T41N, R2W, Sec. 4). Both Ryan and Kurz found outstanding upland sandstone/shale capped bluffs.
Rare & Endangered Species
MDC Natural History inventories documented a total of 43 sites with species of conservation concern within the Bourbeuse River watershed (Table Hc01). The Alosa alabamae (Alabama shad) and the Carpiodes velifer (highfin carpsucker) are the only state-listed fish species in the Natural Heritage Database (see Biotic Section for recent MDC collections). The Alabama shad was collected by Dr. Brooks Burr, Southern Illinois University, Carbondale. The mussel species listed in the Natural Heritage Database as critically imperiled (5 or fewer occurrences statewide) were the Anodontoides ferussacianus (cylindrical papershell), Epioblasma triquetra (snuffbox), Plethobasus cyphyus (sheepnose), and Simpsonaias ambigua (salamander mussel). Additional information regarding state-listed mussel species can be found in the Biotic Section.
MDC fisheries biologists use cedar tree revetments, corridor reforestation, streambank re-vegetation, willow staking, and rock blankets (rip-rap) as stream bank erosion control treatments. These techniques contribute to improved water quality and fish habitat. Once installed, a project on public land can also serve as a local demonstration site of proper stream management techniques and correction (Fantz et al. 1993). The same is true with private land, although the demonstration site aspect depends on the installation agreement with the landowner, as the landowner retains the right to refuse trespass. In 1994, Conservation Department used a cedar tree revetment to stabilize the 396-foot streambank on the Bourbeuse River at T38N, R7W, (Table Hc02). Another streambank stabilization project was installed in 1996 on Robinson Creek, a third-order tributary to the Bourbeuse River watershed. That revetment was installed on a 95-foot long eroding streambank that was 4-6 feet in height.
Stream Habitat Assessment
Following Bovee (1982), the methodology for stream habitat assessment site selection of segments, sub-segments, and representative reaches was based on stream order, flow, and stream complexity within the hydrologic units. Fisheries personnel evaluated habitat on all third-order and larger streams (Figure Hc01). In addition, the site selection procedures, which were similar to those employed for fish community selection, consisted of : (1) constructing gradient plots of potential areas to aid in the selection of sites with various gradients, (2) consulting a topographic map or aerial photos for surrounding land use and access to sites, and (3) viewing video tapes of the watershed areas. Final selection was based on relative differences of the areas, access to the sites, and previously sampled fish community sites. For ease of stream assessment and avoidance of trespass, a ford or a bridge was often near or part of a site. The average length of sites in streams greater than or equal to order 3 was 669 feet. Third- and fourth-order stream sample sites averaged 378 feet in length, and fifth- and six-order stream sample sites averaged 745 feet in length. A sample site or reach consisted of a segment of stream that began with a riffle or pool and ended with a riffle.
Erosional, Corridor, and Land Use Conditions
Soil types, stream corridor, and land use conditions ultimately affect the erosional characteristics of a stream. Silty clays, silty clay loams, and silty loams have an soil erodibility factor of 0.24, 0.37, and 0.43, respectively, representing moderately to highly erodible soils (Table Ge01; Geology Section, Soil Types). Soil types in the Ozark Region are similar to the Ozark Border Region (USDA and SCS 1979). The Soil Survey of Franklin County, Missouri (1989) describes the area that parallels the river as the Haymond-Pope soil association that is composed of alluvium with water erodibility factors of 0.28-0.43. Similarly, the Gasconade County survey in the western portion of the watershed lists the Nolin-Cedargap soil association as the floodplain soil type. Likewise, its water erodibility factors range from 0.10 to 0.43.
Soils along the Bourbeuse River are very deep, well drained, silty, loamy alluvium to somewhat fine sandy loam subsurface layers in some areas or gravelly basal deposits in other subsurface layers (SCS 1989). Following Olsen (1983), soils within the habitat assessment sites were categorized with primary soil descriptors such as gravel (G), sand (S), silt (M), clay (C), organic (O), and peat (Pt), and with secondary descriptors such as well graded (W), poorly graded (P), non-plastic fines (M), plastic fines (C), low plastic fines (L), high plasticity (H), and (BR) bedrock (Olsen 1983). The streambank was broken into soil profile inch groups and assigned descriptors based on the soil’s characteristics. The most common soil typewas clay loam (Figure Hc02, Hc03, Hc04).
Erosion protection comes from a combination of soil type and vegetative characteristics of the stream corridor. Streambank erosion protection was assessed on the left and right streambank within a sample site. Within the entire Bourbeuse River watershed (Figure Hc05, Hc06), sampled sites had 36 streambanks that were completely vegetated with no erosion, 39 streambanks – only isolated bare spots, 17 streambanks – about one-half vegetated, 13 streambanks – most of streambank unvegetated, and three streambanks – completely unvegetated. Comparing Bourbeuse River hydrologic units, the sampled sites in the Upper Bourbeuse River hydrologic unit have the best overall streambank protection and the Little Bourbeuse River hydrologic unit, the worst overall streambank protection.
The bottomland trees and riparian vegetation help protect against erosion especially in areas having highly erodible soils. According to the Franklin County Soil Survey in areas that have the Haymond-Pope soil association, 80% of this association has been cleared of trees and used for cropping and pasture. Within the entire Bourbeuse River watershed (Figure Hc07, Hc08), sampled sites had 45 corridors that were unbroken and more than one tree in width, 10 corridors--a contiguous row of trees along sample sites, 14 corridors--broken along 50% of the corridor length, 17 corridors--limited, present along portion of sample corridor, and 22 corridors--no corridor. Comparing hydrologic units, the sampled sites in the Lower Bourbeuse River hydrologic unit and the Middle Bourbeuse River hydrologic unit have the best overall riparian corridor width and the Little Bourbeuse River hydrologic unit, the worst overall riparian corridor width. Stream roughness components from vegetation and tree roots within a streambank are vital part of the erosion coverage.
Land use on floodplains in the Bourbeuse River watershed is mainly limited to agricultural uses and forested areas. Corn, soybean, wheat, and hay are grown in abundance. Because floodplains are level, they are often chosen for the production of crops (SCS 1989). Observed land use within sampled sites in the Lower Bourbeuse River hydrologic unit showed the predominant uses were from greatest to least: 1) forested lands with livestock excluded, 2) land with row crop and pasture, and 3) home sites and developed land. The lower watershed areas are more urbanized when compared to the Spring Creek, Boone Creek, Red Oak Creek, and the Little Bourbeuse River hydrologic units that are devoted to cattle production. Within these hydrologic units many floodplain areas that were observed contained hayfields, pasture, old fields, and to a lesser degree, forest. Similarly, the Upper Bourbeuse River hydrologic unit was pasture, hayfield, old field, and lastly, forested areas, from most to least observed. Row cropping consumes a major portion of the land use in the Middle Bourbeuse River hydrologic unit.
Channel condition of sampled streams was characterized by evaluating the gravel bar vegetation status. A stable gravel bar contains early succession woody stems. Likewise, an unstable gravel bar has no vegetation or may have annual plants or grasses. Gravel bar stability is a good indicator of overall stream reach stability.
Gravel bars are numerous in the Bourbeuse River watershed. An average of three gravel bars per site of various sizes and with various amounts of vegetation was found within all hydrologic units (HUs). Within habitat sample reaches of the Lower Bourbeuse River HU, 57%, 26%, and 17% of total gravel bars had early successional or woody stems, grasses and sedges, and no vegetation, respectively (Table Hc03). Within the Spring, Boone, Red Oak Creek HU are smaller-order tributaries to the Bourbeuse River. The percentage of the total number of gravel bars within the fourth-order tributaries was 5% early successional or woody stems, 50% grasses and sedges, and 45% no vegetation. Within the Middle Bourbeuse River HU, the sixth-order Bourbeuse River had more stable gravel bars (50% early successional woody stems). Conversely, the smaller-order tributaries generally had more unstable gravel bars with grasses or no vegetation. Combining third to fifth orders within the Middle Bourbeuse River (Table Hc03), 10 out of the 14 gravel bars had grasses and sedges or no vegetation, compared to four out of 14 gravel bars with early successional or woody stems. The same relationship was noted within the Upper Bourbeuse River HU. Approximately 57% of the gravel bars within fourth-order tributaries had no vegetation. Conversely, the main stem Upper Bourbeuse River (fifth order) had 67% of its gravel bars with early successional or woody stems. Sampled gravel bars within stream orders of the Dry Fork and the Little Bourbeuse River HUs indicated that sample site position within the HU was an important determinant in the presence or absence of vegetation on gravel bars. Of the gravel bars sampled, 57% of those within fourth order segments had no vegetation. Although slightly more stable, the fifth-order sample reaches of the Little Bourbeuse River had 50% of the gravel bars with grasses and sedges and 50% gravel bars with no vegetation.
Gravel bars with early successional plants or woody stems are considered more stable than those with grasses or no vegetation. Those gravel bars with little more than grasses or no vegetation are receiving deposition from shifting bed loads from upstream areas and reflect relatively unstable channel conditions. Channel stability, as well as fish habitat, is influenced by a variety of factors such as bed load and gradient. The observation that smaller-order streams have less vegetated gravel bars may suggest that bed load is moving through these streams to the larger-order streams. Stream gradient within the smaller order tributaries is usually higher than larger-order streams. For example, as stream gradient increases upstream from 8-14.5 feet/mile within sample reaches of the Middle Bourbeuse River HU, the number of non-vegetated gravel bars increases. Lower gradient areas are places of gravel deposition and will have both vegetated and non-vegetated gravel bars. For instance, Brush Creek at river mile 8.3 has a gradient of 5.3 feet/mile and several gravel bars with no vegetation and one large bar. A downstream sample site at river mile 5.15 has lower gradient and vegetated gravel bars and few non-vegetated gravel bars. A similar pattern of gravel bars with no vegetation was present in the Dry Fork HU, especially in the losing portion. The sample site at river mile 19.0 had large gravel bars with no vegetation and a gradient of 6.9 feet/mile. The channel is more stable downstream at river mile 8.45 with more large, woody-stem vegetated gravel bars.
Without knowledge of the gravel bar disturbance history, correlating the presence or absence of gravel bar vegetation with land use is somewhat tenuous. However, some evidence of this relationship was suggested in research on the Little Piney River by Jacobson and Primm (1994) and Jacobson and Pugh (1995). According to Jacobson and Primm, prior to European settlement, historic changes in streambed elevations appear to correlate with climatic shifts that suggests a destablization of streams and an influx of gravel. However, research suggests a greater deposition of gravel since European settlement, which is thought to be related to land-use changes after European settlement.
Gravel bars with little or no vegetation may be influenced by land use that affect sheet and rill erosion rates within the watershed (see Geomorphology Section). Changes in the stream channel are influenced by shifting bed load from smaller-order streams. For these reasons, using MoRAP 30-meter resolution TM satellite imagery, an estimate of dominant land use surrounding (generally upstream) the sample sites was determined. From this estimate, a percentage of sites with forest, urban, or woodland and a percentage of sites with cropland or grassland land use for the each HU was determined. The land-use combination is based on the similarity of each in hydraulic properties and erosion resistance. The Lower Bourbeuse River HU had 50% of the land use in cropland/grassland and 50% in forest/urban/woodland (Table Hc03). Compared to other HUs, the Lower Bourbeuse River HU (sixth order) had fewer unstable gravel bars with no vegetation. Other HUs with similar land-use percentages were the Dry Fork HU (fourth order) and the Little Bourbeuse River HU (fifth order). Both of these HUs had unstable gravel bars with grasses or no vegetation. A result which does not necessarily support the relationship between land use and gravel bar stability. The Upper Bourbeuse River HU sample sites appear to have stable gravel bars and more sites with forest/urban/woodland as land use. The observation of streams in the Spring, Boone, and Red Oak creeks hydrologic unit reveals gravel bars with mostly grasses (Table Hc03). Many sample sites in Boone Creek and Red Oak Creek were characterized by pasture or row cropping as the surrounding land use. 37% of the sampled sites had cropland/grassland as land use, considered a potential source of gravel deposition in streams (Table Hc03). Showing a good relationship between land use and gravel bar stability, the Middle Bourbeuse River HU had 67% of the land use as forest/urban/woodland and more early successional or woody-stem vegetated gravel bars than gravel bars with grasses or no vegetation.
These results indicate that while some sampled sites had stable gravel bars and dominant surrounding land use encouraging good soil stability, other sample sites showed little relationship between surrounding land use and gravel bar stability. The results reinforce the concept that the transport and deposition of bed load in streams is influenced by a complex of factors within a watershed. Factors such as channel pattern (straight, meandering, or braided), channel gradient, land use, land cover, flood events, soil types, etc. affect gravel bars, making the analysis of the cause of their instability or stability quite complex.
McCain et al. (1990) developed a channel habitat classification system based on stream channel morphological features and pool-riffle and step-pool formation. A tally of these features was made to provide an estimate of the habitat diversity represented as a percentage composition of habitat types (Figure Hc09). A number of the classifications are good descriptors of Ozark streams. The 22 original McCain et al. (1990) classifications and one additional classification, backwater pool associated with gravel bar (BWPG), were used to describe stream channel morphology (Table Hc04).
McCain et al. (1990) divided habitat types into three categories based on water depth: riffle, run, and pool. Further pool category distinction is based on pool position in the stream (secondary channel, backwater, lateral, and main channel) or the cause of the scour (obstruction, blockage, constriction, or merging flow). Riffle and run are differentiated based on gradient and velocity. Using the river mile and average gradient for the stream segment, we distinguished between low gradient riffle and high gradient riffles.
The low gradient riffle category (LGR) was identified as 22% of the cumulative total types within all sample sites. This was expected because sampling, when possible, included a segment of stream that began with a riffle or pool and ended with a riffle. At times the stream segment sample included two riffles, and possibly, a number of small pools of any given type as described above, separated by a run (7% watershed-wide total) or glide (5% watershed-wide total). Of course, in the smaller-order systems the riffle-pool continuum was closer together; therefore, these segments may have included a pool-riffle-pool-riffle.
During this survey, distinguishing pool types from stream order to stream order improved with experience. Among pool formations, lateral scour was dominant over other pool formations. The lateral scour pool rootwad type was a dominant pool habitat type, accounting for nearly 8% of the habitat types (Figure Hc09). This numerical dominance illustrates the role of a healthy terrestrial-aquatic interface in shaping streams and providing habitat for fish species. The role channel blockage and obstruction from logs and boulders plays in scour pool development is further illustrated by a relative composition of 4.2% (LSPL) and 4% (LSPB), respectively (Figure 14).
Other pool types were mid-channel pool, backwater pool, secondary channel pool, and the corner pool, channel confluence pool, and pocket water pools. First, the mid-channel pool (6.4% watershed-wide total) was a middle channel scour area with low water velocity that may be a transitional area created by shifting bedload. Along with lateral scour pools, these areas are used during fall and winter low water periods. Second, backwater pools ranged in relative composition from 2.1-5.5% watershed-wide total. Mostly used by larval fish and juvenile fish, these were out of the main flow and have low current velocities. These habitats were formed during high flow by rootwad (2.1%), boulders (or in some case concrete; 3.6%), logs (3.9%), or gravel (5.5%). Third, secondary channel pool, formed by merging-flow scour, were fairly common with a composition of 5% watershed-wide total. Fourth, corner pools (3% watershed-wide total) were found in many of the 6th-order stream segments of the Bourbeuse River. Because corner pools are formed by scour and are of large size, they were identified mainly by topographic map. Fifth, the channel confluence pool accounts for 2.1% of the watershed-wide total. Lastly, the pocket water pool was rare in the Bourbeuse River watershed. It accomprised < 1% of the watershed-wide total. This habitat was found at the base of the dam at Noser Mill, where numerous large boulders created small pocket pools from the high flow of the falls.
In addition to the backwater pools, the edgewater areas were important nursery areas for juvenile fish. They typically had emergent vegetation such as waterwillows and are adjacent to riffles or mid-channel pools. Edgewater areas were numerous (8.3% watershed-wide total).
We categorized the human activities in the Bourbeuse River hydrologic units at or near the stream sample sites into 19 categories (Table Hc05). Most sampling was done where low-water crossing or roads were found; therefore, this alteration was noted at many sites.
Agricultural activities were found at nearly all watershed sample sites. First, livestock had access to streams in five of the seven hydrologic unit sample sites. Seven of the thirteen sample sites in the Little Bourbeuse River hydrologic unit had livestock access to streams, making stream sample sites in this watershed the most heavily used by livestock. The Little Bourbeuse River hydrologic unit had the worst riparian corridor and erosion protection condition as compared to other hydrologic units (see Habitat Evaluation Section, Erosion, Corridor, and Land Use Conditions). Although it is difficult to prove relationships between the livestock access and filamentous algae, most sites with livestock access to streams had abundant or some algae (Table Hc05). Lastly, concentrated animal farms were within two of the seven watersheds. The Middle Bourbeuse River and the Little Bourbeuse River hydrologic units had one site each with this activity.
The Middle Bourbeuse River and the Little Bourbeuse River hydrologic units have the most need for management based on the observed scarcity of streambank protection and intact riparian corridors. When comparing across hydrologic units, the Upper Bourbeuse River and the Spring, Boone, and Red Oak Creek hydrologic units may have the best overall watershed conditions within or near riparian zones