Mud Creek Watershed Restoration Plan - Henderson County Center

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Good Sites: Consistent with the WARP study, the most upstream sites show fewer water qualityproblems than sites located in the more developed areas of the watershed. However, even at thegood sites, VWIN noted that nutrient concentrations at the Berea Church Road site have beenunusually high at times and that turbidity, conductivity, lead, and all three nutrient levels at ClearCreek at Apple Valley Road are increasing over time. VWIN concludes that the increasingturbidity levels are probably the result of escalating land disturbing activities.Average Sites: VWIN rates three sites in the Mud Creek watershed, Brittain Creek, Bat ForkCreek, and Mud Creek at 7th Avenue as average. VWIN data indicate that conductivity levelsand heavy metals concentrations in Brittain Creek have been high at times and construction sitesmay be the greatest contributor of sediment to the creek during rains. The site on Mud Creek at7th Avenue shows high concentrations of zinc probably due to road runoff and elevated nutrientconcentrations that may be coming from upstream sources. Diverting wastewater effluent fromthe GE plant to the Hendersonville wastewater treatment plant has helped to improve waterquality in Bat Fork, however nutrients and conductivity levels continue to be abnormally high.VWIN suggests that livestock may be the main source of nutrients to Bat Fork.Below Average Sites: VWIN rates Devil's Fork and Clear Creek at Nix Road (the downstreamsite on Clear Creek) below average. The nutrient and conductivity levels measured at Devil'sFork suggest that agriculture may be the most important source of pollutants to this stream. Bothof these streams have a heavy build-up of sediment in the downstream areas indicating thaterosion and runoff, including sediment pollution from land disturbing activities, have probablybeen impacting these streams for a long time.Poor Sites: Mud Creek at North Rugby Road is one of three sites in Henderson County thatrates poor. This site has consistently rated poor throughout the nine years of analysis. Nutrientconcentrations are much higher than average and water clarity is consistently poor. Nutrientconcentrations increase when stream flow decreases indicating a point-source for thesepollutants. Clear Creek shows serious problems with sedimentation and VWIN indicates thatland disturbing activities are probably a significant factor.2.5.5 Channel and Riparian Buffer ConditionChannel and buffer condition are important indicators of stream habitat and watershed health.Severely eroded streams produce significant quantities of sediment that are carried and depositeddownstream where they smother aquatic habitat. In some cases, channels become so deep andwide that the stream can no longer access the flood plain during a significant storm eventincreasing the likelihood of flooding downstream areas. WARP walked many miles of stream inthe Mud Creek watershed to document channel and riparian buffer condition, however this is avery time intensive effort and they were not able to observe every stream in the watershed. Aspart of the IPSI, TVA also evaluated channel and buffer conditions using aerial photography.These data are useful for documenting areas of the watershed with eroding streambanks andinadequate riparian buffers as well as streams channels that have been altered from their naturalstate.Section 2: Watershed Characterization Page 16
Channelized Streams: Channelization, or the straightening of streams, was a common practicein the Mud Creek watershed to improve drainage and increase valuable floodplain areas forfarming. This practice destroys stream habitat by eliminating riffles and pools and meanderbends. The practice also dramatically affects the watershed hydrology by deepening channels,lowering the water table and increasing the stress on streambanks during storm events. Overtime, channelized streams can become very deep and overly wide with almost verticalstreambanks that can collapse sending large quantities of sediment directly into the stream. If thestreams become very incised, they will no longer over top their banks during storm eventsincreasing the volume and velocity of stormwater to downstream areas.Historical topographic and parcelmaps reveal that large-scalechannelization of Mud Creekoccurred between 1840 and 1890(Figure 2.10). Many tributaries toMud Creek, including Bat Forkand Devils Fork, were alsochannelized. Major floods of1916, 1940, and 1964 caused muchconcern, leading to a number ofstream channelization anddredging projects aimed atminimizing flooding problems.Figure 2.10: Map of Hendersonville showing MudCreek prior to channelization.Table 2.3 illustrates the percentageof stream miles by subwatersheddelineated as channelized by theTVA IPSI. Over 50% of thenatural channels and aquatichabitat of Bat Fork and DevilsFork have been significantlyaltered by this practice. Biologicalmonitoring data collected byWARP in these areas suggests thatloss of habitat in these areas could be impacting the benthic communities in these subwatersheds.Eroding Streambanks: Although severe streambank erosion may be limited to short streamreaches, the sediment pollution from these eroding banks can have impacts throughout thewatershed. The sources of excess sedimentation noted in stream channels throughout the MudCreek watershed are often not readily apparent because the sediment is from erodingstreambanks, and it is then transported and deposited downstream. Table 2.3 illustrates thepercentage of streambank miles that are eroding in each subwatershed as determined by the TVAIPSI from aerial photography. Field assessments conducted by WARP staff suggest that theseestimates are conservative probably due to the limitations of determining eroding banks fromaerial photos. Although the TVA IPSI data indicate that only 18% of the streams in the ClearCreek subwatershed are eroding, a more detailed analysis of these data show that the impact ofSection 2: Watershed Characterization Page 17
Page 1 and 2: Watershed Restoration Plan forthe M
Page 3 and 4: 3.2.2 Strategies to Control Agricul
Page 5 and 6: EXECUTIVE SUMMARYFor the past three
Page 7 and 8: Table ES.1: Proposed management str
Page 9: SECTION 1: PROJECT OVERVIEW1.1 Intr
Page 12 and 13: SECTION 2: MUD CREEK WATERSHED CHAR
Page 14: 2.3 SoilsThree general soil associa
Page 17 and 18: 2.5 Water Quality and Stream Health
Page 19 and 20: To determine the biological health
Page 21 and 22: degradation. In addition, the WARP
Page 23: WARP also evaluated selected metals
Page 27 and 28: 2.6 Local Water Quality Initiatives
Page 29 and 30: Table 2.4: Summary of Zoning in the
Page 31 and 32: The Lawrence Group facilitated a we
Page 33 and 34: SECTION 3: RECOMMENDATIONSBased on
Page 35 and 36: and upper Mud Creek drainages have
Page 37 and 38: Flooding has been a persistent issu
Page 39 and 40: Flat Rock: Consider extending post-
Page 41 and 42: management improvements. Residentia
Page 43 and 44: 3.2 Agricultural Non Point Source P
Page 45 and 46: 3.2.2 Strategies to Control Agricul
Page 47 and 48: The Henderson County Soil and Water
Page 49 and 50: 3.3.2 Strategies to Address Habitat
Page 51 and 52: The Mud Creek Watershed Restoration
Page 53 and 54: Figure 3.10: Percent contribution o
Page 55 and 56: Increasing development in the Mud C
Page 57 and 58: SECTION 4: NEXT STEPS4.1 Present Wa
Page 59 and 60: REFERENCESCenter for Watershed Prot
Page 61 and 62: Technical SubcommitteeAPPENDIX BMud

Mud Creek Watershed Restoration Plan - Henderson County Center

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