Surface Water - Alabama Department of Environmental Management

Cahaba River (0315-0202)
Assessment stations located within the sub-watershed. Descriptions provided in Appendix E-1.
Station Assessment Type Date Location Area
(mi 2 )
CHIL-2
DRY-1
Habitat Biological
Chemical
Habitat Biological
Chemical
Dannelly6 Biological Chemical 2000
Classification
2002 Childers Cr. at AL Hwy 219 5 F&W
2002 Dry Cr. at Dallas CR 201 9 F&W
Cahaba R. approx. 0.5 mi us of confluence
with Dannelly Reservoir
1825 OAW
Cahaba River: Intensive water quality samples were collected monthly during April
through October of 2000 near the mouth of the Cahaba River (Dannelly6) to evaluate
nutrient and sediment loading as a source of water quality impairment to Dannelly
Reservoir (ADEM unpublished res data). The mean total suspended solid concentration at
the Cahaba River embayment was 38.3 mg/L, the highest mean concentration obtained
from reservoir locations within the Alabama River basin. Mean concentrations of
chlorophyll a (9.62 mg/L), total phosphorus (0.027 mg/L), and total nitrogen (0.521 mg/L)
were relatively low in comparison to other tributaries of the Alabama River.
Childers Creek: Sand comprised approximately 90% of the stream bottom of Childers
Creek at CHIL-2 (Appendix J). Habitat quality was assessed as fair due to poor bank
stability and a lack of instream habitat and riparian buffer. The macroinvertebrate
community was assessed as poor (Appendix K). Cattle had direct access to the creek at
several points along the reach. Anaerobic sediments and heavy erosion were noted at the
site. Total suspended solids, total Kjeldahl nitrogen, and chlorides were elevated
(Appendix M).
Dry Creek: Located in the Blackland Prairie (65a) subecoregion, Dry Creek is a claybottomed,
glide-pool stream (Appendix J). Cattle had direct access to Dry Creek at DRY-
1. Moderate erosion and filamentous green algae observed at the site suggested in-stream
scouring and nutrient enrichment to be potential problems. Instream habitat was limited by
the large proportion of hard-pan clay and low flow. The macroinvertebrate community was
assessed as good (Appendix K).
Water quality data collected during May of 2002 showed elevated concentrations of
total dissolved solids and chlorides (Appendix M). The fecal coliform count was 210
colonies/100 mL (Appendix M).
Sub-watershed status: A 4.5 mile segment of Dry Creek is impaired by pathogens from
pasture grazing. ADEM’s TMDL for this polutant was approved during 2003. Habitat and
biological conditions in Childers and Dry Creek were assessed as impaired during
assessments conducted in 2002. Pasture grazing, aquaculture, and septic tank failure were
the main NPS concerns in the sub-watershed.
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