The Tennessee Cave Salamander (Gyrinophilus palleucus). Photo courtesy of Tom Barr.
NOTE: This is a draft of a report I am preparing for City Council on the environmental impacts of the proposed James White Parkway extension. Comments are are welcome. For maps and descriptions of the proposed road, visit the website for South Knoxvillians Advocating Reasonable Development (SKARD) (CLICK HERE).
Introduction: the human and environmental character of South Knoxville
The portion of South Knoxville through which the proposed extension of the James White Parkway (JWP) passes is home to well-established neighborhoods, to some remarkable geological features, and to unique and valuable flora and fauna. An extensive and largely undeveloped natural corridor, some of it spectacularly scenic, extends southwestward from the Tennessee and French Broad Rivers at Ijams Nature Center, Forks of the River Wildlife Management Area and Burnett Creek valley through Meades Quarry, along the western bank of Toll Creek and to the peaks and deep valleys along both sides of Redbud Road. This corridor, though close to downtown Knoxville, is rugged and predominantly wooded. Water flows from many small springs and seeps into three major streams: Toll Creek, Baker Creek and Burnett Creek. In low-lying areas, sinkholes abound, some draining directly into the large and ecologically significant Meades Quarry Cave system (described below).
On the steep ridges a rich oak-hickory forest supports a surprising variety of birds, including (among many others) scarlet tanagers, indigo buntings, red-eyed vireos, wood thrushes and red-shouldered hawks. Where the soil is thin, there are cedar barrens, dotted with patches of native prickly pear cactus and inhabited by field sparrows, prairie warblers, eastern towhees and the rare and declining yellow-breasted chat. At the end of the existing roadway, directly in the path of the extension, lies a forested wetland populated by huge old oaks and hickories.
Homes in the vicinity of the proposed roadway are modest and suburban, some still containing farm buildings reflective of the area's rural heritage. In the vicinity of South Doyle Middle School and again at Island Home Pike, Prospect Road and Old Sevierville Pike, the proposed roadway cuts through relatively densely populated, long-established suburban neighborhoods.
Caves and cave systems near the proposed parkway
Of perhaps greatest ecological importance are the caves. There is strong evidence that Meades Quarry Cave system lies beneath the proposed roadway. According to Chris Kerr, a prominent local caver:
It should be noted that if the stream passage in Meades Quarry Cave continues as a low horizontal canyon to near Old Sevierville Pike, Meades Quarry Cave itself would approach a mile in length and the likelihood of extending the drainage basin to the southwest—towards Cruze Cave—dramatically increases.
There is, furthermore, evidence that a second cave whose entrance lies just to the west of Cruze road, approximately half a mile to the south of the proposed JWP extension, is part of the Meades Quarry Cave System. This evidence takes three forms. The first is positional: Meades Quarry Cave runs southwest from its entrances in the general direction of Cruze Cave, a little over a mile away. Second, both caves and the sinkhole complex just mentioned lie within the Holston Formation, a long band of relatively soluble marble-like limestone known as "Tennessee marble" that is in this area only a few hundred yards wide. Because it is more soluble than the surrounding strata, the Holston Formation defines the most likely route for an underground watercourse to follow. Third, Addison Wynn of the National Museum of Natural History in Washington, who has studied the Berry Cave Salamander in both caves, reports:
The Meades Quarry Cave system may be even more extensive, for there is nearby yet a third cave, Johnson Cave, whose vertical entrance lies on private land about a quarter mile north of Meridian Cemetery. The entrance to Johnson cave lies within a few hundred feet of the western boundary of the proposed JWP extension. Johnson Cave has also apparently not been well-explored but seems to extend in the direction of the proposed route. It is listed on the Generalized Geologic Map of Knox County (1973) as belonging to a contiguous group of caves that includes Cruze Cave and two other South Knoxville Caves, Brown Cave and Backyard Cave.
Safety problems associated with the caves
The occurrence of such a large cave system beneath the proposed roadway raises, first of all, a safety issue: is the cave system deep enough and the overburden strong enough to prevent the road from collapsing? We do not know exactly where the cave passages are in relation to the road, nor how deep. Nevertheless, it seems very likely that the large complex on the northeastern edge of the proposed Redbud interchange leads into the Meades Quarry Cave system, and that the proposed road and associated interchange passes over the cave system in this vicinity. Construction of such a large road will certainly cause substantial changes in surface drainage. Thus arise several concerns, which are best explained by quoting the Tennessee Division of Geology Bulletin 70 (1973), entitled Geology of Knox County, Tennessee:
Permanent control of this type of subsidence is practically impossible, as underground solution of limestone and dolomite is one of the inexorable forces of nature. (p. 87)
Presence of rare, threatened or endangered species
The area to be impacted by the proposed roadway contains some extraordinarily sensitive wildlife habitat. Unfortunately, TDOT failed to recognize this when it designed the JWP extension. TDOT's March 2001 Environmental Assessment of the final 2.3 miles of the proposed extension of the parkway states, "There were no sensitive locations identified in or immediately adjacent to the proposed project corridor, and there were no federal or state-listed threatened and/or endangered species locations identified within the vicinity of the proposed corridor." (p. 3-9) However, the Division of Natural Heritage of the Tennessee Department of Environment and Conservation, indicated this past summer (August 2002) that the following species of concern have been documented in the vicinity of the proposed James White Parkway extension:
The Berry Cave Salamander (Gyrinophilus gulolineatus) is a unique and extremely rare animal, having been verifiably observed in only four locations in the world, all of them in East Tennessee. It was originally discovered Berry Cave in Roane County, where a viable population still exists. Later it was found in Mud Flats Cave in west Knox County, but this habitat has severely degraded recently by silt from the Gettysvue housing development. Recent efforts to find the salamander there have failed, and this population may now be extirpated. Two specimens were once found in a ditch near Athens, but nobody knows how they got there or whether they represent some still extant population in that area. The only other place where the salamander has been found is the Meades Quarry/Cruze cave complex. South Knoxville thus contains one of only two known extant populations.
The Berry Cave Salamander was originally classified as a subspecies of the Tennessee Salamander (Gyrinophilus palleucus; see illustration below)—which was declared the state amphibian of Tennessee by an act of the State Legislature in 1995. However, according to the most recent taxonomies, it is in fact a separate species. The Berry Cave Salamander is thus in biological fact an endangered species, though not officially listed as such. It is, in any case, certainly an organism in need of special protection. Threats to either of its two known locations must be taken seriously.
The U.S. Fish and Wildlife Service has been actively collecting data on both the Tennessee Cave Salamander and Berry Cave Salamander (it held a meeting for this purpose in Cookeville on December 10, 2002) and is considering its "elevation to candidate status" for the federal Endangered Species List. Due, however, to politically motivated funding restrictions imposed by Congress in 1994, no new species (no matter how endangered) are being added to this list and none is likely to be added in the near future. The Tennessee Wildlife Resources Agency (TWRA) currently lists the Tennessee Cave Salamander as "Threatened." This listing includes the Berry Cave Salamander, which TWRA still lists as a subspecies of the Tennessee Cave Salamander.
The Tennessee Cave Salamander (Gyrinophilus palleucus). Photo courtesy
of Tom Barr.
It should be noted that the Berry Cave Salamanders so far collected from Meades Quarry and Cruze caves have hybridized with the Spring Salamander (G. Porphyriticus), which occurs near the caves' mouths. But Addison Wynn of the National Museum of Natural History believes that pure specimens may occur deep in the caves, since the farther in the specimens are collected the more genetically pure they are.
It appears that Johnson Cave, which is also very close to the proposed roadway, has never been checked for salamanders. If it is indeed part of the same system as the Meade Quarry and Cruze caves, it is possible that Berry Cave Salamanders occur there as well.
There is also reason to suspect that gray bats sometimes use the Meades Quarry Cave system. Records from the U.S. Fish and Wildlife Service indicate that gray bats are known from three locations near Knoxville. Gray bats require caves with high ceilings and permanent streams, characteristics found in fewer than five percent of caves. Meades Quarry cave has these characteristics. In a report on the Meades Quarry Cave system, written this year (summer, 2002) Chris Kerr observes:
Threats to threatened or endangered species
The proposed road as currently designed constitutes a demonstrable and significant threat to the habitat of the Berry Cave Salamander and also to the habitat of gray bats, if they use the caves.
Berry Cave salamanders feed on invertebrate fauna that in turn consume organic material washed into the caves from sinkholes. Thus damage to the sinkholes leading into the cave system can disrupt the food chain on which the salamanders depend. As was noted above, an especially large sinkhole complex occurs southeast of the intersection of Redbud Drive and Sevierville Pike at the northeastern edge of the proposed Redbud interchange. This sinhole complex lies in the Holston formation, approximately half way between the mouths of Meades Quarry and Cruze caves, and it almost certainly drains into the Meades Quarry Cave system at each of its multiple drain points. Building the road as planned on the steep slope immediately above and very near to the sinkholes could significantly affect the volume of organic matter entering the cave system and hence the food chain on which the salamanders depend. The difficulty of the situation is compounded by the fact that efforts to control runoff could also reduce the amount of organic matter entering the cave, once again diminishing the salamanders' prey.
Siltation is another serious concern. It has already been noted that the Berry Cave Salamanders that once inhabited Mud Flats Cave appear to have been extirpated by siltation. That this is a possibility in South Knoxville is demonstrated by the fact that severe erosion has occurred in the portion of the parkway already completed. The sidewalk along a considerable portion of Cottrell Street just south of Antia Drive, for example, is completely buried in mud to a depth of several inches. The mud originated as erosion from a bank cut by TDOT to build the existing portion of the parkway. Road cuts for the proposed extension of the JWP are quite large, especially in the vicinity of the sinkhole complex just mentioned, which lies at the bottom of a steep slope traversed by the proposed road.
Yet another concern is that the volume of water entering the caves could be altered by changes in drainage and surface water flow. Once again, the Redbud interchange presents special problems. With so large an impervious asphalt surface so close to sinkholes, it is likely that during heavy rains water would enter the sinkholes in much greater volume and much more rapidly than it does now. Moreover, during the summer months, this water would sometimes be running off hot asphalt, creating thermal pollution. These alterations in both water volume and water temperature could be detrimental either directly to the salamanders or to the invertebrates on which they feed.
Other potential sources of damage to salamander habitat include filling of cave passages with concrete, collapse of cave passages (either during of after construction), pollution from toxic runoff, and toxic chemical spills (which must be anticipated with a road of this nature)—all of which could harm the salamanders, either directly or by reducing their prey. Toxic runoff and spills from the road might enter the cave system either through sinkholes or by percolating through the soils above.
If endangered gray bats use the cave system, their habitat could be degraded by direct destruction of cave passages, alteration of air flow in the caves, and degradation of nearby foraging habitat. The breaching of a passage connecting to the cave system by the roadcut would likely alter air-flow patterns through the cave, potentially damaging the bats' cave habitat, since bats are extremely sensitive to changes in air temperature.
Moreover, the foraging habitat of gray bats include heavily vegetated streams within a radius of approximately five miles from the cave entrances. Baker Creek, Toll Creek and Burnett Creek are all heavily vegetated where the proposed road crosses them; hence, if these bats are present, there would also be significant potential for damage to their foraging habitat.
Wetlands and surface water
Just past the end of the currently existing portion of the James White Parkway lies a wooded wetland. The trees there are exceptionally old and large, and the wetland is habitat to a variety of species of birds. Bats have also been observed foraging there. Water from the wetland appears to drop into underground caverns though openings a foot or more in diameter visible in the wetland itself. Therefore, this is one of the many areas of concern with respect to sinkholes. The JWP extension would pave over and destroy this wetland.
The proposed roadway crosses Baker Creek near Taylor Avenue, Toll Creek near Island Home Pike and two substantial branches of Baker Creek, one just south of Prospect Road and the other north of Meridian Cemetery. The JWP extension may be expected to lower water quality in these three creeks, by adding to the silt load, especially during construction, and by contributing additional nonpoint runoff (leaking gas, oil, antifreeze, brake fluid, etc., as well as occasional accidental spills of toxic materials) and litter from the completed roadway.
Hazardous waste sites
A significant and highly controversial hazardous waste site occurs on the Regan property just off of Sevierville Pike near the proposed parkway. Demolition materials contaminated with PCB's, diesel fuel, creosote and other toxic materials were dumped in a sinkhole there.
The EPA also lists a dump site on Cruze Road in the near vicinity of the proposed parkway extension on its list of CERCLIS Hazardous Waste Sites, site number TN0001921477. EPA first considered it on June 9, 1997. The state considered it on Feb. 13, 1998, but did nothing. EPA still lists it as needing a site investigation. According to some old geological records, the city used to dump garbage there. A neighbor reports that "the government" buried radioactive material in this dump, but this is unsubstantiated. However, given the vicinity of the Witherspoon sites along Maryville Pike (which are known to be contaminated with radioactive materials from the nuclear weapons plants at Oak Ridge) it is probably worth following up on this.
Effects of the construction especially with regard to the Regan property site should be more carefully evaluated than they have been so far.
"Ghettoization" of surrounding neighborhoods
Building an interstate-style highway through suburban neighborhoods will clearly not increase the quality of life in these neighborhoods. Traffic noise will increase. Noise may be especially troublesome, due to the noise canyon effect, where the road cuts deeply into hills. There will be local increases in air pollution as well. The noise and pollution are of especial concern given the proximity of the proposed road to South Doyle Middle school.
As with many other TDOT projects, including the initial portion of the JWP, there is likely to be damage to nearby homes from blasting. The extension is also likely to bring an increase of littering into South Knoxville, as is evidenced by the extensive littering along existing portion of parkway and its access roads.
Pedestrians and bicyclists will find it difficult to get from one side to the other of neighborhoods that are bisected by the road, making local transportation more difficult. This is a problem with the existing portion the JWP, which cut off several east-west transportation routes for local bike, pedestrian and automobile traffic. This, again, is of special concern near South Doyle Middle School.
The parkway extension will also be detrimental to the aesthetics of South Knoxville. People frequently remark on the "desolate" quality created when the original portion was built with such a huge, treeless cross-section. The JWP extension, as currently planned, would extend this "desolate" quality to a much larger area.
This great expanse of asphalt will also store and radiate a significant quantity of heat, largely in areas now shaded by trees, making neighborhoods near the road hotter and less hospitable on hot summer days.
Quality of life in neighborhoods near the road may thus be expected to deteriorate significantly, making properties in its vicinity less desirable and creating a "ghettoization" effect in a broad swath across South Knoxville.
Sprawl
It is clear that the JWP extension is designed to provide convenient access to I-40, I-75 and downtown Knoxville from Sevier and southern Knox Counties and that it would, as a result encourage urban sprawl. Knoxville already suffers from sprawling development. The most recent and comprehensive nationwide study addressing this issue is Measuring Sprawl And Its Impact: The Character & Consequences of Metropolitan Expansion, by Reid Ewing, Rolf Pendall and Don Chen (Smart Growth America, 2002). According to this study, among the nations 83 largest metropolitan areas, metropolitan Knoxville had the eighth worst overall score for sprawl and the eighth worst raking for good neighborhood mixes of homes, offices and shopping areas. Sprawl is a serious issue here, and the JWP extension would worsen the problem.
The alternative of improving Chapman highway seems far preferable in this regard. As the Knoxville News-Sentinel noted with regard to the study just mentioned:
Park loss
Knoxville's newly-created Marie Myers Park, which covers an area of about 3.9 acres and serves to provide bird habitat and urban forest, lies directly in line with the proposed roadway. The James White Parkway extension as currently planned would destroy the park. Yet if the road were not built, this park could be a node in an extraordinarily large and valuable urban forest corridor stretching from Ijams Nature Center and Forks of the River Wildlife Management Area, through Meades Quarry and up into the hilly forests along Redbud Avenue.
Conclusion: preserving South Knoxville's neighborhoods and natural heritage
The proposed road would create significant environmental deterioration to several South Knoxville neighborhoods and to a unique urban natural area, threatening rare cave ecosystems, fragmenting surface habitat, destroying an urban wetland and reducing water quality. It would permanently disrupt the integrity of what is now an unusual and largely intact urban forest. Little has been done in the current design to minimize these impacts, some of which have not even been acknowledged by TDOT. Whether or not the road is eventually built, we can and should do better.