These are the potential impacts of development on Ebenezer Swamp and the surrounding area:

• Alteration of water cycle in the swamp (i.e. the swamp dries up)

• Accelerated sinkhole development in the surrounding area

• Increased downstream flooding

• Impairment of public and private drinking water supply

Dear Friends of Ebenezer Swamp:

I am certain that you will be concerned about recent developments that pose a great risk to the health and longevity of the wetland. The Middle Tennessee Land Development LLC has proposed opening a limestone quarry in the southern Cahaba Valley, adjacent to Ebenezer Swamp and the headwater of Spring Creek. This is dire news! A limestone quarry in this location will have widespread and profound effects on the ecology of the region. It will adversely impact the local flora and fauna as well as the people that live in the area. These effects will likely include: extirpation of local plant and animal species due to loss of wetland habitat, higher average stream flows with more-frequent and more-severe downstream flooding, increased downstream sedimentation, contamination of aquifer-supplied drinking water, loss of aquifer-supplied drinking water, and accelerated sinkhole development in the surrounding highlands. These effects will be a direct and unavoidable consequence of the geology and hydrology of the region.

The entire Cahaba Valley is underlain by carbonaceous sediments (i.e., limestone). Limestone is a vital natural resource and as such has a market value, which drives the extraction of the mineral. The limestone beds beneath the Cahaba Valley are fractured and chambered creating a natural aquifer filled, like a giant sponge, with groundwater. Groundwater in this aquifer is tapped for drinking water by several municipalities (e.g., Alabaster, Calera, and Montevallo) in the region. Spring Creek drains the upper portion of the southern Cahaba Valley and flows through the center of Ebenezer Swamp, a classic upland hardwood swamp. Upland hardwood swamps are one of the most-rapidly disappearing habitats in the southeastern United States. The surface of Spring Creek generally coincides with the top of the groundwater. That is to say, groundwater, in seeking its own level, saturates the lowest elevations of the surrounding terrain. Historically, many naturally-flowing springs were also present along the margins of Spring Creek; however, the springs along southern Spring Creek no longer flow (see below for reason), while the ones along upper Spring Creek continue to flow. Ebenezer Swamp has formed in the extensive saturation zone along the margins of Spring Creek. This saturation zone is caused by the combined inputs of groundwater and surface water. During summer months, when surface water input is negligible, groundwater input ensures that the stream continues to flow and that the surrounding soils remain wet. The hydrologic balance between groundwater and surface water sustains the attendant swamp ecology.

A limestone quarry operation will have a major effect on the local hydrologic balance. Quarries quickly become ponds if they are not continuously pumped dry because of the continuous influx of groundwater. Dewatering operations continuously withdraw groundwater from the aquifer and divert it as surface flow. The larger the hole, the greater the volume that must be pumped out. The net effect of pulling groundwater out of the bottom of a quarry is to create a large “cone of depression” in the surrounding water table that reaches well beyond the quarry’s perimeter. Dry Valley, which is situated to the east of the southern Cahaba Valley and is home to extensive quarry operations, provides clear and compelling examples of the effects of dewatering. In the early 1970s the dewatering rate from the Dry Valley quarries was approximately 14,000 gallons per minute. More recent data are not available publicly, but given the increasing sizes of the quarries, today’s pumping volume must be considerably greater. All wells less than 100 feet deep in the vicinity of the Dry Valley quarries are dry. Aerial photography shows scores of sinkholes, and the natural springs that used to feed lower Spring Creek, in the adjacent watershed, have gone dry. The diverted groundwater flows out of Dry Valley as surface water in Dry Creek, where it subsequently joins with Spring Creek, which then joins with Shoal Creek, which then flows through Montevallo before joining with Mahan Creek to form the Little Cahaba River.

Dewatering in the vicinity of Ebenezer Swamp would lower the groundwater surface to a point below the natural outflows of the existing springs, causing the springs to go dry. Concomitantly, a lowered groundwater surface would reduce the overlaying saturation zone, thus causing the soils along the stream flanks to dry out leading to a loss of habitat. Normal groundwater inputs into Spring Creek and Ebenezer Swamp occur slowly and steadily. Increase in surface water input due to dewatering will far exceed the loss of groundwater input because the volumes pumped from the quarry will be greater than the volumes usually flowing from the springs. Because surface water moves relatively quickly out of the watershed, aquifer recharge through the stream bottom will be very limited. The net effect will most likely be the loss of swamp habitat, to be replaced by a drainage creek. Many of the hundreds of plant and animal species that inhabit Ebenezer Swamp will be extirpated. The beneficial aspects of the wetlands (i.e., water purification, bank stabilization, and storm runoff holding capacity) will be lost.

As you well know, Ebenezer Swamp is home to hundreds of species of fungi, plants, and animals and is also the site of a 65 acre preserve conserved by the University of Montevallo. Ebenezer Swamp is used by the University of Montevallo for teaching and research purposes. The forest is dominated for the most part by Tupelo Gum (Nyssa aquatica), with occasional Red Mapel (Acer rubrum), Loblolly Pine (Pinus taeda), Sweet Bay (Magnolia virginiana), Tulip Tree (Liriodendron tulipifera), and Sycamore (Platanus occidentalis). The dominant animal life form is the Beaver (Castor canadensis); water impounded behind several beaver dams along Spring Creek has a pronounced effect on the ecology of the preserve. Other animal inhabitants include the American Woodcock (Philohela minor), Turkey (Meleagris gallopavo) Great Blue Heron (Ardea herodia), Timber Rattlesnake (Crotalus horridus), Water Moccasin (Agkistrodon piscivorus), Copperhead (Agkistrodon contortrix) Raccoon (Procyon lotor ), Opossum (Didelphis marsupialis virginiana), and various species of freshwater clams. The preserve is also home to numerous herbaceous plant species, including four species of orchids (Platanthera flava, Ponthieva racemosa, Listera australis, and Tipularia discolor) and a rare species of cone-flower (Rudbeckia auriculata). Ebenezer Swamp is used by the University of Montevallo for teaching and research purposes. Spring Creek and Ebenezer Swamp form a portion of the headwaters for the ecologically diverse and environmentally sensitive Cahaba river watershed. The Cahaba is the longest remaining free-flowing river, has more species of fish per mile than any river in North America, and is one of eight river biodiversity hotspots in the U.S. Destruction of Ebenezer Swamp will further the ongoing degradation of the Cahaba river watershed.

A quarry operation in southern Cahaba Valley will not only devastate the ecology of Spring Creek, but it will also affect the people that live in the region. The southern Cahaba Valley is already home to many people and new developments are going in almost daily in this area of explosive population growth. Quarry-associated sinkhole developments will place financial burdens on homeowners and their insurers. Noise and dust produced by quarry operations will have a high nuisance value. Many homes are situated on the adjacent ridge lines, locations that will provide homeowners with unobstructed views of daily quarry operations. Quarry-associated vehicular traffic will only exacerbate existing and growing problems of traffic congestion. Increased surface runoff will pose problems for the city of Montevallo. As previously mentioned, the waters of Spring Creek eventually flow through Montevallo as Shoal Creek. Shoal Creek already carries the dewatering inputs from Dry Valley and adding water from a quarry operation in the southern Cahaba Valley will only increase its average daily stage and gauge. Downstream residents should expect more frequent flooding and higher flood levels during peak rain events. Three municipalities draw portions of their drinking water from the underlying aquifer by wells. Drinking water supplies could become contaminated during quarry operations by the spillage or dumping of petroleum products and chemicals, this would increase the cost of necessary water purification. Further, if the groundwater level is lowered to a point below the well bottoms they will go dry.

I assure you that a quarry operation in southern Cahaba Valley poses many associated risks to the ecology of the region. These risks have the potential to bring great harm to all life forms in the area as well as financial hardship to the people of the region. I am asking you to help prevent the loss of yet another piece of Alabama’s natural wealth, please write or call the individuals on our contact list and tell them of your concerns and opposition to the Middle Tennessee Land Development LLC’s quarry proposal.

Thank you for your help,

 

T. M. (Mike) Hardig, Ph.D.
Associate Professor