Harpeth River, Tennessee: Technical Appendices

Appendix A: Acronyms & Abbreviations Appendix B: Study Area Maps

Appendix C: Scoping Letter, Responses, & Letters of Intent Appendix D: Hydrology & Hydraulics

Appendix E: Hazardous, Toxic, & Radioactive Waste

Appendix F: References

Appendix A

Acronyms & Abbreviations

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Appendix A Acronyms & Abbreviations Acronyms and Abbreviations BMP Best Management Practice

BWSC Barge, Waggoner, Sumner, and Cannon

CE Common Era

DO Dissolved Oxygen

FEMA Federal Emergency Management Agency

FIRM Flood Insurance Rate Map

FRM Flood Risk Management

HRWA Harpeth River Watershed Association

HTRW Hazardous, Toxic, and Radioactive Waste

IA Individual Assistance

Metro Metropolitan Nashville

MS4 Municipal Separate Storm Sewer System

NED National Economic Development

NER National Ecosystem Restoration

SR State Route

TDEC Tennessee Department of Environment and Conservation

TWRA Tennessee Wildlife Resources Agency

WMA Wildlife Management Area

WRDA Water Resources Development Act

Harpeth River, Tennessee 1 Appendix A May 2012

Appendix B

Study Area Maps

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Appendix B Study Area Maps

Harpeth River, Tennessee 3 Appendix B May 2012

Appendix B Study Area Maps

Harpeth River, Tennessee 4 Appendix B May 2012

Appendix B Study Area Maps

Harpeth River, Tennessee 5 Appendix B May 2012

Appendix C

Scoping Letter, Responses, and Letters of Intent

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Appendix C Scoping Letter, Responses, and Letters of Intent Scoping Letter

Harpeth River, Tennessee 1 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent Scoping Letter Responses

Harpeth River, Tennessee 2 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 3 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 4 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 5 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 6 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent Letters Of Intent

Harpeth River, Tennessee 7 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 8 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 9 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 10 Appendix C May 2012 Appendix C Scoping Letter, Responses, and Letters of Intent

Harpeth River, Tennessee 11 Appendix C May 2012

Appendix D

Hydrology & Hydraulics

I. Flood Risk Management Analysis

II. Nashville Flood Preparedness

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Appendix D Hydrology & Hydraulics

I. Flood Risk Management Analysis As part of the post-May 2010 flood recovery work, separate from this reconnaissance effort, the U.S. Army Corps of Engineers, Nashville District (Corps) began a watershed analysis of the Harpeth River Basin in cooperation with Metropolitan (Metro)-Nashville government. The goal of the work was to develop updated hydrologic information related for flooding within the basin for use in new flood warning tools and for local planning. This information was also provided to the Federal Emergency Management Agency (FEMA) for use in updating local Flood Insurance Rate Maps as part of a current effort within the county.

The Corps was provided the newest LiDAR data available in the Metro area, and used State LiDAR data for areas outside Davidson County. The LiDAR data from the confluence with the Cumberland River upstream to the Davidson/Williamson County line was of good quality, but the grid became coarser inside Williamson County. The coarse LiDAR data was acceptable for use with HEC-GeoHMS to collect geometric information for the HEC-HMS rainfall runoff model used in the study, but was deemed inappropriate for use with HEC-GeoRAS to collect geometric data for the HEC-RAS model. Because of this, the Corps created an HMS model of the entire basin, but only created a RAS model of the Harpeth River from the mouth upstream to the Davidson/Williamson County line.

The Corps was able to calibrate the models to known events, and replicated the May 2010 inundation. These models were used to perform cursory evaluations of flood risk measures proposed in the study reach as described later in this appendix. For the portion of the basin upstream of Davidson County, the Corps did not create an HEC-RAS model to evaluate alternatives, but a model may be available in the future because FEMA is using the Corps model as a starting point to model the remainder of the river to the headwaters using new LiDAR. A great deal of the assessment, in terms of enumerating at-risk structures, was done by map reconnaissance using available aerial photography. It is recognized that with any vintage photography other than something recently completed there is risk of missing structures that are more recent, or including structures that may have been removed.

Flood Risk Management from the Mouth of the Harpeth Through Bellevue, Tennessee

The historic May 2010 flood saw flooding in the vicinity of Harpeth Meadows Drive, Hickory Drive, Saunders Lane, Harpeth View Trail, Bluff View Drive, Quail Covey Trail, Riverview Drive, Zapata Drive, Canoe Court, Trading Post Court, Settlers Court, Boone Trace, Beautiful Valley Drive, Settlers Way, Valleypark Drive, Claytie Circle, Londonberry Road, Staffordshire Drive, Sunderland Circle, Rolling River Parkway, Scenic Valley Lane, Somerset Farms Circle, US 70/I-40 Intersection, General George Patton Road, Morton Mill Road, Todd Preis Drive, Plantation Court, Beech Bend Drive, SR 100, Yearling Way, Tern Court, Sparrow Court, Rock Wall Road, and others. This is as far upstream as the Nashville Flood Preparedness HEC-RAS model extends. Each of these streets is in the area of predominantly residential or mixed commercial development.

Additionally, the Harpeth River created its own high-flow relief in the vicinity of river mile (RM) 42.65 (near the Kingston Springs exit on I-40) during the May 2010 flood. The flow re-entered the river in the vicinity of RM 38.05. Several structures, including homes, were destroyed or damaged as a result of the river cutting off the bend at this location. A local elementary school, Kingston Springs Elementary School, was flooded by backwater from the river near this location.

Flooding of homes during the May 2010 flood along Cunningham Court on the left bank of the Harpeth River in Kingston Springs, Tennessee (vicinity Harpeth River Mile (HRM) 36.2). Based on GIS reconnaissance it appears that 19 homes may have been affected by flooding during this event.

Harpeth River, Tennessee 1 Appendix D May 2012 Appendix D Hydrology & Hydraulics Additionally, the sewage treatment plant may have been isolated by floodwaters, if not directly impacted. However, none of these structures are affected by any event less than the May 2010 flood, which exceeded the 0.2% annual chance exceedence event in this area. Staff of the Town of Kingston Springs reported that flood waters from the May 2010 event inundated the lagoon at the treatment plant and damaged a number of sanitary sewer pump stations.

In this area the depths of flooding during the May 2010 event were up to approximately four feet. Two options are apparently available in this location. The first may be to raise the homes in place due to the relatively low depth of flooding. However, this method may not be appropriate if the homes are slab- on-grade. Further investigation of this method may be necessary. A second option may be to construct 4,000 linear feet of levee that ties to high ground on each side of the neighborhood. This length would also enclose the treatment plant and preserve access to the plant during a recurrence of the May 2010 event or other flood that would prevent access. The height of the levee would be 22 feet plus any necessary freeboard to protect up to the May 2010 event, and would require a pump station for interior drainage.

Flooding of homes during the May 2010 flood along East Kingston Springs Road, Maple Court, Acorn Court, Hickory Drive and Harpeth View Trail on the left bank of the Harpeth River in Kingston Springs, Tennessee. This area is affected by riverine flooding and lies partially along a natural cutoff channel that operates during the 4% annual chance exceedence and larger events. The upstream end of the cutoff is near HRM 42.5, and the outlet is near HRM 37.9. Based on GIS reconnaissance it appears that 35 homes may have been affected by flooding during this event and two homes were completely destroyed. Fewer than 10 of the homes appear to be affected by events smaller than the May 2010 flood.

In this area the depths of flooding during a recurrence of the May 2010 event range from 2 feet to 11 feet. There is one home that may be in the revised floodway. All homes except 2 are above the 100 year flood. 500-year flood depths range up to 6 feet. In these structures, depths may be too great to raise (again dependent upon construction type) or for floodproofing, and therefore, the only potential mitigation may be buy-out and evacuation.

Flooding of homes during the May 2010 flood along Riverview Drive, Elkmont Place, Bluff View Drive, Riverchase Court and Elkmoore Drive on the left bank of the Harpeth River in Cheatham County, Tennessee (vicinity HRM 45.7). Based on GIS reconnaissance it appears that 27 homes may have been affected by flooding during this event. The homes may also be subject to flooding during the 0.2%, 0.5% and 1% annual chance exceedence events based on the newest, but not yet adopted, stream profiles. Additional homes may be affected, but the age of the aerial photography precluded a better count.

In this area the depths of flooding during a recurrence of the May 2010 event ranged up to 4.5 feet, with more shallow flooding during the 100-, 200-, and 500-year events (1’ to 3’). These structures may be eligible for raise-in-place, dependent upon construction type. Alternately, 5,800 linear feet of levee and a pump station to remove interior drainage could also protect the structures.

Flooding of homes during the May 2010 flood along Zapata Drive on the right bank of the Harpeth River in Cheatham County, Tennessee (vicinity HRM 47.6). Based on GIS reconnaissance it appears that 25 homes may have been affected by flooding during this event. Some of the homes may also be subject to flooding during the 0.2%, 0.5% and 1% annual chance exceedence events based on the newest, but not yet adopted, stream profiles.

In this area the depths of flooding during a recurrence of the May 2010 event ranged up to 15 feet, with the 100-year up to 8 feet, and the 50-year storm up to 6.5 feet affecting only seven homes. Options in

Harpeth River, Tennessee 2 Appendix D May 2012 Appendix D Hydrology & Hydraulics this vicinity may be raise-in-place for some, or buy-out and evacuation for those experiencing deep flooding. An alternative may be to construct 4,000 feet of levee to protect the entire area, and include a pump station to remove interior drainage. One complication may be construction room given the proximity of the proposed floodway.

Flooding of homes during the May 2010 flood along Boone Trace, Canoe Court, Settlers Court and Beautiful Valley Drive on the left bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 50.2). Based on GIS reconnaissance it appears that 85 homes may have been affected by flooding during this event. Many of the homes may also be subject to flooding during the 0.2% and 0.5% annual chance exceedence events based on the newest, but not yet adopted, stream profiles, but fewer than 10 would likely be affected during the 1% event.

A recurrence of May 2010 would produce inundation depths in this area range up to 8 feet, with most in the 3 feet range. In these homes it may be possible to raise-in-place, dependent upon construction type, or to buy-out and evacuate.

Flooding of homes in the Bending River Drive, Harpeth Run Drive, Riverview Bend Drive, Riverfront Drive area on the left bank of the Harpeth River in Davidson County (vicinity HRM 50.6 to 51.7). The age of available aerial imagery precluded a home count in this area, but homes do exist along these streets.

In most of this area a recurrence of the May 2010 inundation depths ranged up to 11 feet. Possible solutions include 3,000 linear feet of levee with a pump station to remove interior drainage during flood events, limited raise-in-place for structures of the appropriate construction type and depths of flooding, or buy-out and evacuation for structures that cannot be protected by other means. In the area of Riverfront Drive the May 2010 event flooded to depths up to 7 feet. Protection of this area would require 4,000 linear feet of levee with a pump station, or limited raise-in-place, or buy-out and evacuation. Construction type and depth of flooding would govern the non-structural approach to mitigation here.

Flooding of homes during the May 2010 flood along Coley Davis Road on the right bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 54.1). Based on GIS reconnaissance it appears that apartment buildings/townhomes may have been affected by flooding during this event. These homes may also be subject to flooding during the 0.2% annual chance exceedence event based on the newest, but not yet adopted, stream profiles.

At this location the depth of flooding for a recurrence of the May 2010 event was approximately 5 feet, and the 500-year flood would be approximately 2 feet deep. It may be possible to protect these structures using raise-in-place techniques, or to construct 1,000 feet of levee tied to high ground at the ends, with a pump station to remove interior drainage.

Flooding of homes during the May 2010 flood along Claytie Circle, Onslow Way, Vauxhall Drive, Claytie Court and Sunderland Circle in the River Fork Subdivision and Rolling River Parkway in the Rolling River Subdivision on the left bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 56.1 to 56.8). Based on GIS reconnaissance it appears that 93 homes may have been affected by flooding during this event. Some of the homes may also be subject to flooding during the 0.2% and 0.5% annual chance exceedence events based on the newest, but not yet adopted, stream profiles.

These homes flood to depths up to 8 feet during a recurrence of the May 2010 event, 4 feet during the 500-year event, and 3 feet during the 200-year event. The 200-year event affects approximately 15

Harpeth River, Tennessee 3 Appendix D May 2012 Appendix D Hydrology & Hydraulics homes that may be eligible for floodproofing or raise-in-place. It may be possible to protect all homes affected up to the 500-year event by raise-in-place if the homes are of the appropriate type of construction and the depth of flooding is not too great.

Flooding of homes during the May 2010 flood along Summerview Court and Somerset Farms Circle on the right bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 57.0). Based on GIS reconnaissance it appears that 18 homes may have been affected by flooding during this event. Some of the homes may also be subject to flooding during the 0.2% annual chance exceedence event based on the newest, but not yet adopted, stream profiles.

The depth of flooding in this area during a recurrence of the May 2010 flood ranges up to 2 feet, with lesser events producing only very shallow flooding. If the construction type is appropriate, flood damage mitigation may be achieved through raise-in-place.

Flooding of homes during the May 2010 flood along General George Patton Road, Sawyer Brown Road and connecting internal streets on the right bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 58.3 to 59.3). Based on GIS reconnaissance it appears that 196 townhome structures may have been affected by flooding during this event. These structures may be dual units, or two homes per structure. Some of the structures may also be subject to flooding during the 0.2% and 0.5% annual chance exceedence events based on the newest, but not yet adopted, stream profiles.

The Metro Nashville Unified Flood Preparedness team identified 5,800 linear feet of levee as an alternative to protect this area. The depth of inundation is approximately 1 foot for the 200-year event, and ranges up to 4 feet for a recurrence of the May 2010 event.

Flooding of homes during the May 2010 flood along Leblanc Court, Morrisey Court, Harpeth Mill Court, Harpeth Lake Court, Morton Mill Court, Morton Mill Road, Northridge Drive and South Glenleigh Court on the left bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 59.3). Based on GIS reconnaissance it appears that 80 homes may have been affected by flooding during this event. Several of the homes may also be subject to flooding during the 0.2%, 0.5%, and 1% annual chance exceedence events based on the newest, but not yet adopted, stream profiles.

In this area a recurrence of the May 2010 event would produce inundation ranging up to 10 feet in depth, and the 200-year event would produce inundation up to 7 feet deep. There does not appear to be any affected structures during the 100-year event. Due to the infrequent inundation, space restrictions due to the proximity of the roadway, a greenway and the river, no alternative was identified at this location.

Flooding of homes during the May 2010 flood along Beech Bend Drive, Harpeth Bend Drive and Footpath Terrace on the right bank of the Harpeth River in Davidson County, Tennessee (vicinity HRM 61.0). Based on GIS reconnaissance it appears that 156 homes may have been affected by flooding during this event. Several of the homes may also be subject to flooding during the 0.2%, 0.5%, and 1% annual chance exceedence events based on the newest, but not yet adopted, stream profiles.

The Metro Nashville Unified Flood Preparedness team identified 6,000 linear feet of levee as an alternative to protect this area. The depth of inundation is approximately 2 feet for the 100-year event (affecting few homes), 4 feet for the 200-year event (affecting 75% of the homes in the neighborhood), 7 feet for the 500-year event (affecting 95% of the homes in the neighborhood), and ranges up to 9 feet for a recurrence of the May 2010 event.

Harpeth River, Tennessee 4 Appendix D May 2012 Appendix D Hydrology & Hydraulics SR 100 overtopped during the 4% and larger annual chance exceedence events in the vicinity of HRM 62.1. The overtopping occurs in the left bank approach to the highway bridge at this location.

SR 100 is a major arterial road leading to Nashville from areas to the west of the city. The western approach appears to overtop at the 50-year event with 8 feet of inundation, and ranges up to 15 feet for a recurrence of the May 2010 event. For the 500-year event and above, both approaches and the bridge overtop, making modifications infeasible. However, during the 200-year event the depth of inundation is 10 feet, and again only the western approach overtops. This important access may be improved by raising the western approach to the desired level of protection. This would require the acquisition of additional right-of-way and raising approximately 1,400 linear feet of the road.

Kingston Springs Elementary School in the vicinity of HRM 37.6 was flooded during the May 2010 flood. The updated, but not yet adopted, hydraulic model shows that the school may be in the 500-year floodplain but appears to be above the 100-year floodplain and, with the exception of the lower driveway, above the 200-year floodplain. The school is affected by backwater flooding from the Harpeth River. There is a small stream that drains the area around the school that has not been evaluated for flooding potential due to the small tributary area. A local protection project such as a levee might be appropriate to protect the school from the 500-year storm or a repeat of the May 2010 flood. The 500- year level of protection would require a levee/floodwall that was approximately 12 feet tall at its highest, tapering to natural ground, approximately 650 feet long, a low level outlet with closure structure, and closure structures on the driveways unless the driveways could be relocated. Protecting to the May 2010 level would require the same features but the levee/floodwall would be approximately 20 feet at its highest and be approximately 1000 feet long.

A summary table of this analysis of the Harpeth River from the mouth through Bellevue is found below in Table 1, with a corresponding map of locations in Figure 1.

Harpeth River, Tennessee 5 Appendix D May 2012

Appendix D Hydrology & Hydraulics Table 1 - Harpeth River Damage Centers from May 2010 Flood Event, the mouth of the river through Bellevue, Tennessee. A map of these locations is found in Figure 1 Map and Model Reconnaissance, From the Mouth through Bellevue, Tennessee Map Stream Vicinity RM May Event Measures Considered Description Index Total Structures Impacted Figure 1 19 homes on Cunningham Court were inundated by depths up to approximately 4 feet. May 2010 floodwaters also inundated a wastewater treatment plant lagoon in this area. Raising Harpeth 36.2 19 Raise Homes in Place, Levee homes in place or a 4,000 foot floodwall are considered viable options here for addressing the 1 floodwaters. These structures do not appear to be affected by flood events with a frequency of less than 0.2% Kingston Springs Elementary School & 3 Kingston Springs Elementary School was inundated during the May 2010 event. Updated flood Harpeth 37.6 Levee 2 Residences frequency profiles indicate that the school may fall within the 500 year floodplain. 35 homes along E. Kingston Springs Rd, Maple Ct., Acorn Ct., Hickory Dr., and Harpeth View Trail appear to have been inundated in the May 2010 event. At least two homes in this area Harpeth 37.9 to 42.5 35 Evacuation 3 were completely destroyed. May 2010 inundation in this area ranged from 2 to 11 feet. Two of these 35 structures are below the 100 year floodplain. 27 homes along Riverview Dr., Elkmont Pl., Bluff View Dr., Riverchase Ct., and Elkmoore Dr. were affected by the May 2010 flood. These homes may be affected by flood events as frequent Harpeth 45.7 27 Nonstructural, Levee 4 as the 100 year event. May 2010 flooding ranged up to 4.5 feet with more frequent events ranging from 1 to 3’ 25 homes along Zapata Dr. may have been affected by the May 2010 flood event. Some of Harpeth 47.6 25 Nonstructural, Evacuation, Levee 5 these homes may also be affected by flood events as frequent as the 100 year event. 85 homes along Boone Trace, Canoe Ct., Settlers Ct., and Beautiful Valley Dr. appear to have been affected by the May 2010 flood event. Many of these homes appear to be affected by less Harpeth 50.2 85 Nonstructural ,Evacuation 6 frequent events than the May 2010 event. Inundation depths in these affected homes ranged from 3 feet to 8 feet in these homes in May 2010. The lack of aerial imagery precluded an accurate structure count of this area along Bending River Dr., Harpeth Run Dr., Riverview Bend Dr., and Riverfront Dr. However, it is known that Harpeth 50.6 to 51.7 Total Count Unknown Levee, Nonstructural, Evacuation 7 there are structures in this area that experienced inundation depths ranging up to 11 feet in May of 2010. The lack of aerial imagery precluded an accurate structure count of this area along Coley Davis Harpeth 54.1 Total Count Unknown Levee, Nonstructural, Evacuation Road, but there are apartment buildings or townhomes that appear to have been inundated up 8 to 5 feet in May of 2010. 93 homes along Claytie Cr., Onslow Way, Vauxhall Dr., Claytie Ct., and Sunderland Cr. May Harpeth 56.1 to 56.8 93 Nonstructural have been affected by the May 2010 flood event. Inundation depths in these homes ranged up 9 to 8 feet, and are estimated at 3 feet at the 200 year flood event. 18 homes along Summerview Ct. and Somerset Farms appear to have been affected by the Harpeth 57 18 Nonstructural May 2010 flood event. Inundation depths during the May 2010 event were in the neighborhood 10 of two feet, with very shallow flooding at more frequent events. 196 townhome structures along General George Patton Rd., Sawyer Brown Rd., and Harpeth 58.3 to 59.3 196 Levee connecting streets appear to have been inundated in the May 2010 flood event. Inundation 11 depths from the 200 year event to the May 2010 event range from 1 to 4 feet in this area. 80 homes along Leblanc Ct., Morrisey Ct., Harpeth Mill Ct., Harpeth Lake Ct., Morton Mill Ct., Morton Mill Rd., Northridge Dr., and South Glenleigh Ct. appear to have been inundated in the Harpeth 59.3 80 Nonstructural 12 May 2010 flood event. Several of these homes may be subject to flood in as frequent as the 100 year event. 156 homes along Beech Bend Dr., Harpeth Bend Dr., and Footpath Terrace appear to have Harpeth 61 156 Levee have been affected by the May 2010 flood event. Several of these homes may also be affected 13 by floods as frequent as the 100 year event. The western approach of SR 100 appears to overtop at approximately the 50 year event. It is also noted later in the report, but there appears to be scour behind the pier on the right bank. Harpeth 62.1 SR 100 Bridge Bridge & Approach Modifications 14 While it does not appear to threaten the pier, it may threaten the foundation of the adjacent structural bent.

Harpeth River, Tennessee 6 Appendix D May 2012

Appendix D Hydrology & Hydraulics

Figure 1 - Primary Flood Damage Sites, Harpeth River from Mouth through Bellevue, Tennessee

Harpeth River, Tennessee 7 Appendix D May 2012

Appendix D Hydrology & Hydraulics

Unified Flood Preparedness Plan – Metro Nashville

Metro Nashville’s Unified Flood Preparedness Plan is an effort ongoing at the time of the writing of this report. In this program, Metro Nashville is looking at flood risk management alternatives to be employed on the six streams of greatest potential flood risk within Davidson County. These are the Cumberland River, Harpeth River, Mill Creek, Whites Creek, Browns Creek, and Richland Creek. For each of these streams, primary damage centers have been identified and alternatives are being developed and modeled using models created by the Corps for Metro Nashville. A summary of the preliminary alternative analysis is outlined below. Section II of this Appendix contains further information on the Unified Flood Preparedness Plan analysis.

The effort to model alternatives began using the model that was submitted to AECOM for review and incorporation into the FIS update for Metro-Nashville Davidson County. Barge, Waggoner, Sumner and Cannon (BWSC), acting as a consultant to Metro-Nashville, provided a matrix of alternatives to the Unified Flood Preparedness team for consideration. The Corps was tasked to prepare a cursory screening-level evaluation of the structural alternatives proposed. The sections below provide discussion of the alternatives modeled. The 50-, 100-, 200-, 500-, and May 2010 profiles were modeled for this effort. Harpeth River Miles (HRMs) referenced below were provided by BWSC, and the corresponding model stations are shown in parentheses beside the HRM.

The analysis described below is summarized in Table 2, following.

Modifications to the I-40 bridge at HRM 53.51 (283650)

This alternative was delivered as a simple increase in bridge opening. BWSC did not identify the extents to which the bridge opening was to be increased. The Corps assumed an increase of 200 feet toward the left bank. This alternative would require excavation of the left approaches and natural ground on the downstream side of the left approach to create more hydraulic opening, and the installation of piers, beams and decking. The downstream cross section was modified to increase the available conveyance, and at 200 feet increase, the low chord was approximately 7 feet above the ground on the upstream side. There was negligible effect on the 500-year profile, and the profiles for the 200-year event and below were reduced by approximately 0.32 feet.

The result of this modification was to decrease the May 2010 profile by approximately 0.68 feet, and effectively converge to the base profile 5.7 miles upstream.

Modifications to the CSX Bridge at HRM 53.89 (285709)

This alternative was not modeled since the proposed revised profiles greatly overtop the bridge for the analyzed discharges.

Modifications to the CSX Bridge at HRM 56.72 (300809)

This alternative was inundated at the 200-year event and above, and caused headlosses in all profiles above the 50-year event. The geometry for this bridge was modified by adding 100 feet of bridge opening to each approach (200 feet total), and more modern piers at the locations of the current abutments. This modification lowered the May 2010 profile by 0.16 feet, the 500-year profile by 0.49 feet, the 200-year profile by 0.79 feet, the 100-year profile by 0.72 feet and the 50-year profile by 0.10

Harpeth River, Tennessee 8 Appendix D May 2012 Appendix D Hydrology & Hydraulics feet. The 50-year profile converged to the base profile by the next upstream bridge, while the others effectively converged by the upstream Davidson County line.

Modifications to the CSX Bridge at HRM 57.88 (307033)

This alternative was inundated at the 200-year event and above, and caused headlosses in all profiles. The geometry for this bridge was modified by adding 200 feet of bridge opening, and more modern piers to keep the spans relatively short. Structural design may be able to lengthen the spans. Relative low chord and low chord slopes were maintained in the bridge opening. This modification lowered the May 2010 profile by 0.49 feet, the 500-year profile by 0.48 feet, the 200-year profile by 1.10 feet, the 100-year profile by 1.30 feet and the 50-year profile by 2.25 feet. The differences converged in minor amounts up to the upper limit of the model at the upstream Davidson County line.

Modifications to the Old Harding Road Bridge at HRM 59.16 (313669)

This alternative was not modeled because the bridge overtops at the 50-year event and above and has limited head loss through the bridge (0.65’+/-). Overtopping occurs in the left approach that would make bridge modifications less effective.

Modifications to the S.R. 100 Bridge at HRM 61.78 (327938)

This alternative may provide some relief to areas outside Davidson County, inside Williamson County, if the bridge opening was increased. The bridge bisects a large bend in the river, and enlarging the bridge opening would subject adjacent fields to more flowing water than might be experienced at this time. Detailed surveys of the bridge superstructure, substructure, approaches and adjacent floodplains could provide better data upon which to base an opinion and conduct more detailed analyses. This alternative was not modeled at this time because the new model stops immediately upstream of the bridge. AECOM may extend the model into Williamson County as part of the FIS update. Further consideration of this alternative for flood damage reduction in Williamson County is recommended since the bridge causes significant headlosses of up to 0.75 feet for the 5- through 50-year events.

Cumulative Effects of Modifying Bridges at HRM 53.51, 56.72 and 57.88

These bridges were considered together to determine the effects of modifying all three in unison. The bridge openings were widened similarly to the individual cases noted in the previous discussion. The water surfaces were no different in the combined run for the reach between the bridges at HRMs 53.51 and 56.72. Between HRMs 56.72 and 57.88 the May 2010 profile was lowered by 0.73 feet, the 500- year profile was lowered by 0.64 feet, the 200-year profile was lowered by 1.08 feet, the 100-year profile was lowered by 1.03 feet and the 50-year profile was lowered by 0.23 feet, as compared to the base profile. These differences represent improvements in the water surface profiles in this reach of up to 0.57 feet at the May 2010 event above the single bridge option for this reach. From HRM 57.88 to the upstream terminus of the model the May 2010 profile was lowered by 0.66 feet, the 500-year profile was lowered by 0.97 feet, the 200-year profile was lowered by 1.83 feet, the 100-year profile was lowered by 1.30 feet and the 50-year profile was lowered by 2.37 feet. These differences represent improvements in the water surface profiles in this reach of up to 0.73 feet at the 200-year event above the single bridge option in this reach. It seems that the best results are provided by modifying all three bridges as opposed to individual bridges.

Construction of a Diversion Channel Cutting Off the Bend Between HRMs 57.99 and 56.72

Harpeth River, Tennessee 9 Appendix D May 2012 Appendix D Hydrology & Hydraulics This alternative was suggested by the Metro-Nashville consultant, and the Corps prepared a cursory analysis for screening purposes. The proposed alternative includes the construction of approximately 3,000 linear feet of diversion channel that is twenty feet wide at the bottom, five feet deep and has 3:1 side slopes. The diversion channel was designed with the bottom below the 2-year water surface profile elevation and the effects on the 50-year through May 2010 profiles were analyzed. Based on the preliminary HEC-RAS analysis, it appears that this alternative has the potential to lower the water surface profiles immediately upstream of the cutoff channel by amounts ranging from 2.0 feet during the May 2010 event to 3.9 feet during the 50-year event, with the other frequency events ranging between those values. At the upper end of the study reach the values ranged from 0.91 feet to 1.3 feet for the same events. This alternative shows some promise, but should be developed in detail and the hydrologic routing taken into account to ensure conditions are not changed downstream.

Installation of Levees at HRM 58.2 (307103)

This alternative, discussed in section II of this appendix, was identified by BWSC for the Metro Unified Flood Preparedness team as having potential for flood damage mitigation for homes on the right bank of the Harpeth River at this location. The option included 6,000 linear feet of levee and a pump station to remove interior drainage. The Corps included the levee in a geometry data set for the HEC-RAS model to determine the effects of the alternative on natural flood profiles. This option caused an increase of 0.15 feet during a recurrence of the May 2010 event, an increase of 0.12 feet for the 200-year event, and did not affect lesser events. The levee alternative caused an increase of up to 0.21 feet per second in velocities in the study reach, and did not appear to have additive effects on the levee alternative at HRM 60.3.

Installation of Levees at HRM 60.3 (318385)

This alternative, discussed in section II of this appendix, was identified by BWSC for the Metro Unified Flood Preparedness team as having potential for flood damage mitigation for homes on the right bank of the Harpeth River at this location. The option included 5,800 linear feet of levee and a pump station to remove interior drainage. The Corps included the levee in a geometry data set for the HEC-RAS model to determine the effects of the alternative on natural flood profiles. This option caused an increase (0.03 feet) during the 100-year discharge, and larger increases for events up to the recurrence of the May 2010 event, which had a maximum increase of 0.15 feet. It should be noted that since this alternative is very near the upstream end of the model, and thus the county line, that effects beyond this limit are not quantified. Events lower than the 50-year discharge were unaffected by the alternative.

Installation of a Dry Reservoir at Lumpkins Bridge Road in Williamson County

This alternative was given a cursory evaluation using HEC-HMS by modifying the model calibrated and used to develop frequency discharges for the HEC-RAS model used for the Unified Flood Preparedness project. The Corps evaluated the proposal using elevation-storage data provided by BWSC, and controlling the outlet to obtain a maximum pool elevation while allowing just over 3 feet of freeboard to remain. Storage information was given in acre-feet for elevations 690 (19,640) and 700 (44,760). The results of the HMS analysis show that this alternative may hold promise for significant reduction of discharges through the City of Franklin and parts of Williamson County, but that the reductions in discharge drop to 5.9% for the 100-year event at the Bellevue gage. At the Kingston Springs gage the discharges converge to without-reservoir magnitudes. In the Franklin reach, 100-year discharges were reduced by approximately 90% in the preliminary analysis. Since the reductions were realized in the

Harpeth River, Tennessee 10 Appendix D May 2012 Appendix D Hydrology & Hydraulics reach above the HEC-RAS model terminus, no HEC-RAS runs were done to develop inundation and depth grids.

Pump/Levee Combination at HRM

The two variations of this alternative involved installing a pump station to alleviate backwater flooding on the north side of I-40 in the vicinity of the Highway 70 interchange with I-40. One variation involved installing a pump station that is designed to keep backwater flooding at or below an elevation of 550’. The other variation involved installing a pump station that involved keeping backwater flooding at or below 556’.

Harpeth River, Tennessee 11 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Table 2 - Summary of alternatives analyzed for Metro Nashville Unified Flood Preparedness Plan

Unified Flood Preparedness Plan, Nashville, Tennessee Alternative Vicinity RM Effects Does this Alternative Warrant Further Study? Modifications to I-40 Bridge 53.51 Inadequate No Modifications to CSX Bridge 53.89 No

Modifications to CSX Bridge 56.72 Inadequate No Modifications to CSX Bridge 57.88 Inadequate No Modifications to SR 100 Bridge 61.78 Unknown Yes, due to such significant headloss at bridge 53.51, 56.72, Potential Yes, Although construction costs are likely too great Cumulative Effects of Bridges 57.88 Diversion Channel 56.72 to 57.99 Potential Yes, Although construction costs are likely too great Protection at Less Frequent 58.2 Yes, Although damages are infrequent Levees Events Protection at Less Frequent 60.3 Yes, Although damages are infrequent Levees Events Dry Reservoir at Lampkins Bridge 102.7 Potentially Significant Protection Yes Road Pump/Levee Combination 57.2 No, Costs are likely far greater than benefits

Harpeth River, Tennessee 12 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Flood Risk Management Upstream of Bellevue, Tennessee

There are varying degrees of development along the river and its tributaries, with many structures located within the 1% (100-year) floodplain in the portion of the Harpeth River basin that drains Williamson County. A number of structures were noted to be within the 10% (10-year) floodplain as well during the map reconnaissance. Based on available information, many structures were identified that could benefit from non-structural approaches to flood damage mitigation. Additionally, one previously identified location near the headwaters of the main stem could potentially offer relief through storm water detention and significantly reduce discharges in the river from Franklin to Bellevue. This measure could alleviate flooding of structures up to the 1% flood, and therefore could also reduce the flooding impact of the 10% flood. Many of the smaller tributaries are too densely developed to allow effective regional storm water detention for flood mitigation, but opportunities may exist on the larger tributaries as indicated in the text below. Detention on the larger tributaries could be an effective mitigation strategy on each of the affected tributaries, and contribute to flood damage reduction along the Harpeth River. Along the Harpeth River and its tributaries listed below 857 structures were identified that appear to be within the 1% floodplain. Of these structures 163 appear to be within the 10% floodplain. Those in the 10% floodplain are primarily along the main stem, and in backwater areas of the tributaries. Regional storm water detention could be very effective in mitigating losses in these structures. Detailed analyses of the effects of detention in the tributary basins should be performed during the feasibility phase to see if detention in a single basin, or combination of basins, could provide effective flood damage mitigation to a greater extent, and in a more cost effective manner, than more isolated non-structural measures. Regional storm water detention in this area may provide more relief in Franklin/Williamson County and Bellevue/Davidson County than in areas further downstream due to basin timing considerations and the portion of the Harpeth River basin effectively controlled by detention structures. However, the implications of upper- and mid-basin storm water detention cannot be fully and accurately quantified for the entire river without detailed analyses.

The reconnaissance analysis described below is summarized in Table 3, following, with Figure 2 and Figure 3 depicting the locations described.

Harpeth River Main Stem

In the vicinity of stream mile 77.58 there is a wastewater treatment plant within the 1% floodplain that is apparently affected by the 10% floodplain as well. If the plant is currently in use it may be possible to protect the plant with a ring levee or floodwall.

In the vicinity of stream mile 82.56 there are 14 commercial/industrial structures within the 1% floodplain that may benefit from non-structural measures.

In the vicinity of stream miles 83.93 to 84.09 there are 96 residential and 11 commercial/industrial/institutional structures in the 1% floodplain, 38 of which are in the 10% floodplain. Some of these may be candidates for non-structural measures or a flood warning system.

In the vicinity of stream mile 86.14 there are 25 residential structures (one repetitive loss) that are within the 1% floodplain, three of which are in the 10% floodplain. Inundation depths appear to range from 6 to 14 feet.

In the vicinity of stream miles 86.55 to 86.77 there are seven commercial/industrial structures in the 1% floodplain, one of which is in the 10% floodplain, and three of which are affected by the floodway. Depth of flooding is approximately eight feet.

Harpeth River, Tennessee 13 Appendix D May 2012 Appendix D Hydrology & Hydraulics

In the vicinity of stream miles 87.46 to 88.04 there are 52 structures in the 1% floodplain, 12 of which are in the 10% floodplain. Five structures are repetitive loss structures that may be on the list for evacuation.

In the vicinity of stream mile 88.26 there are four structures in the 1% floodplain.

In the vicinity of the confluence with Watson Branch to Harpeth River stream mile 89.21 there are 25 structures in the 1% floodplain, one of which is in the 10% floodplain. These may benefit from non- structural measures.

In the vicinity of stream miles 89.38 to 90.03 there are six structures in the 1% floodplain, one of which is in the 10% floodplain. Some of the structures may benefit from non-structural measures, but the structure in the 10% floodplain has a water depth of approximately 13 feet.

In the vicinity of stream mile 95.57 there is one structure potentially affected by the 1% floodplain. This structure may be a candidate for non-structural measures due to the apparent shallow flooding.

In the vicinity of stream mile 97.11 there are five structures potentially in the 1% floodplain, one of which is in the 10% floodplain. Three of the structures appear to be agricultural structures, and the other two may be homes. One home appears to be in the 10% floodplain with a depth of inundation near 12 feet. The other home may be in the 10% floodplain. The three other structures have depths of approximately three feet, but may be ineligible for non-structural measures.

In the vicinity of stream mile 99.10 there is one home in the 1% floodplain that may benefit from non- structural measures due to apparently shallow flooding.

In the vicinity of stream mile 101.95 there are two homes in the 1% floodplain that may benefit from non-structural measures, although the flooding depth appears to be in the range of six feet.

In the vicinity of stream mile 105.82 there is one home in the 1% floodplain. Approximate flooding depths were unavailable.

In the vicinity of stream mile 110.52 there is one structure in the 1% floodplain. Approximate flooding depths were unavailable.

The total number of potentially affected structures is 252, 58 of which may be in the 10% floodplain, based on a count from available aerial mapping.

It appears that regional detention may be useful to reduce flooding along the Harpeth River and could provide relief for less frequent events. This could potentially affect the entire reach and benefit numerous structures and lessen the non-structural commitment. There are areas throughout the basin that may be available to provide storage, either individually or in combination that could increase the effectiveness of this measure.

Harpeth River Tributary 1

There are no apparent structures within the 1% floodplain.

Little Harpeth River

Stream miles 2.55 to 3.4 there are 24 structures within the 1% floodplain, seven of which are within the 10% floodplain.

Harpeth River, Tennessee 14 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Stream miles 4.94 to 8.34 there are 163 structures within the 1% floodplain, 81 of which are within the 10% floodplain.

In the vicinity of stream mile there are six structures within the 1% floodplain.

The total number of potentially affected structures is 193, 88 of which may be in the 10% floodplain, based on a count from available aerial mapping.

Along the main stem of the Little Harpeth River it appears that in some cases non-structural measures may be appropriate for flood loss mitigation, and that regional detention should be investigated as a possible measure that could reduce flooding and the need for non-structural measures. This stream contains repetitive loss structures that are apparently slated to be evacuated.

Little Harpeth River Tributary 1

There are fifteen structures in the 1% floodplain. Non-structural measures may be appropriate for this location. Regional detention does not appear to be a potential measure because of the size and extent of development of the subbasin. Stream miles are not referenced due to the short length of the stream.

The total number of potentially affected structures is 15 based on a count from available aerial mapping.

Little Harpeth River Tributary 2

There are five structures in the 1% floodplain. Non-structural measures may be appropriate for this location. Regional detention does not appear to be a potential measure because of the size and extent of development of the subbasin. Stream miles are not referenced due to the short length of the stream.

The total number of potentially affected structures is five based on a count from available aerial mapping.

Little Harpeth River Tributary 3

There are four commercial structures in the 1% floodplain. Non-structural measures may be appropriate for this location. Regional detention does not appear to be a potential measure. Stream miles are not referenced due to the short length of the stream.

The total number of potentially affected structures is four based on a count from available aerial mapping.

Little Harpeth River Tributaries 4 & 6

These streams are considered together since they appear to be the same stream on the aerial photography. Above the I-65 crossing at Tributary 4 mile 0.90 to Tributary 6 mile 0.30 there is a flat pool that inundates one institutional structure and 76 residential structures in the 1% floodplain. The headloss through the I-65 Bridge and Railroad Bridge immediately downstream is 22 feet, and may be excessive. This area should be re-studied in detail using appropriate hydrologic methods and candidates for non-structural measures identified, or bridge improvements analyzed.

The total number of potentially affected structures is 77 based on a count from available aerial mapping.

Harpeth River, Tennessee 15 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Little Harpeth River Tributary 5

There are five commercial structures and 11 residential structures in the 1% floodplain. The inundation depths are approximately 7 and 10 feet, respectively, based on readily available information. This area may benefit from a flood warning system.

The total number of potentially affected structures is 16 based on a count from available aerial mapping.

Little Harpeth River Tributary 7

In the vicinity of stream mile 0.93 there are two structures within the 1% floodplain that may be aggravated by backwater from a local street crossing. In the vicinity of stream mile 1.04 there are three structures affected by backwater from I-65 (4’) and three structures that are affected by 2-3 feet of backwater from a local street crossing. Each of the eight structures may benefit from non-structural measures. Increased conveyance in the crossings may be another possible measure.

The total number of potentially affected structures is eight based on a count from available aerial mapping.

Little Harpeth River Tributary 8

In the vicinity of stream mile 0.35 there are two structures that are affected by six feet of backwater from I-65, and in the vicinity of stream mile 0.39 there are four structures affected by three feet of backwater from a local street crossing. Improved crossings may also be a possible measure at these locations.

The total number of potentially affected structures is six based on a count from available aerial mapping.

Little Harpeth River Tributary 10

Most homes in the 1% floodplain are marked as repetitive loss structures and are likely slated for evacuation. There are two homes in the vicinity of stream mile 1.08 that could benefit from non- structural measures or from enlarging the culvert crossing immediately downstream. There are two homes in the vicinity of stream mile 1.28 that may have potential for non-structural measures.

The total number of potentially affected structures is four based on a count from available aerial mapping.

Little Harpeth River Tributary 11

There are three homes in the 1% floodplain in the vicinity of stream mile 0.27 that appear to be inundated from backwater from I-65. There is one home in the vicinity of stream mile 0.13 in the 1% floodplain. Each of these may benefit from non-structural mitigation measures.

The total number of potentially affected structures is four based on a count from available aerial mapping.

West Harpeth River

In the vicinity of stream mile 7.03 there are three structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

Harpeth River, Tennessee 16 Appendix D May 2012 Appendix D Hydrology & Hydraulics

In the vicinity of stream mile 7.40 there are three structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

In the vicinity of stream mile 8.47 there are two structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

In the vicinity of stream mile 11.01 there is one structure potentially affected by the 1% floodplain that may benefit from non-structural measures.

The total number of potentially affected structures is nine based on a count from available aerial mapping.

The West Harpeth River may contain opportunities for regional detention that could alleviate flooding on the West Harpeth River and on the Harpeth River downstream of the confluence.

Murfrees Fork of the West Harpeth River

In the vicinity of stream mile 3.84 there are four structures potentially affected by the 1% floodplain, one of which appears to be in the regulatory floodway. The structure that appears to be in the floodway looks like a barn on the available aerial photography. Depth of flooding appears to be sufficiently shallow that non-structural measures may benefit the other structures.

In the vicinity of stream mile 6.75 there are two structures that are potentially affected by the 1% floodplain. These structures may benefit from non-structural measures due to apparent shallow flooding.

The total number of potentially affected structures is six based on a count from available aerial mapping.

Murfrees Fork may contain opportunities for regional detention that could alleviate flooding on this stream, the West Harpeth River and on the Harpeth River.

Arrington Creek Main Stem

There are no apparent structures within the 1% floodplain.

Arrington Creek Tributary 1

There is one structure apparently within the 1% floodplain adjacent to the stream.

Arrington Creek Tributary 2

There are no apparent structures within the 1% floodplain.

Arrington Creek Tributary 3

There is one apparent barn that may be affected by the 1% floodplain.

Arrington Creek Tributary 4

There are two barns that may be affected by the 1% floodplain.

Harpeth River, Tennessee 17 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Arrington Creek Tributary 5

There are no apparent structures within the 1% floodplain.

Beech Creek

In the vicinity of stream mile 1.72 there are three structures potentially affected by the 1% floodplain. These may benefit from non-structural mitigation measures.

In the vicinity of stream miles 2.39 to 3.62 there are 22 structures potentially affected by the 1% floodplain that may benefit from non-structural measures. These structures are too high in the watershed to benefit from regional detention.

The total number of potentially affected structures is 25 based on a count from available aerial mapping.

Burke Branch

In the vicinity of stream mile 1.05 there are two homes that appear to be in the 1% floodplain. These homes may benefit from non-structural measures due to apparently shallow flooding.

In the vicinity of stream mile 1.32 there are two homes that appear to be in the 1% floodplain. These homes may benefit from non-structural measures due to apparently shallow flooding.

The total number of potentially affected structures is four based on a count from available aerial mapping.

Cartwright Creek

In the vicinity of stream mile 0.65 there are twelve structures potentially affected by the 1% floodplain. These structures are located just outside the Harpeth River backwater effects. These structures may benefit from non-structural measures.

In the vicinity of stream mile 0.82 there is one commercial structure potentially affected by the 1% floodplain. This structure may benefit from non-structural measures.

In the vicinity of stream miles 0.82 to 1.37 there are sixteen structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

In the vicinity of stream mile 1.82 there are sixteen structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

In the vicinity of stream mile 2.28 there are two structures potentially affected by the 1% floodplain that may benefit from non-structural measures.

There does not appear to be a viable opportunity for regional detention in the Cartwright Creek subbasin.

The total number of potentially affected structures is 47 based on a count from available aerial mapping.

Leipers Fork Creek

In the vicinity of stream mile 1.68 there are seven structures potentially affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

Harpeth River, Tennessee 18 Appendix D May 2012 Appendix D Hydrology & Hydraulics

In the vicinity of stream mile 3.08 there are three structures potentially affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

In the vicinity of stream mile 3.80 there is one structure potentially affected by the 1% floodplain. Due to apparently shallow flooding this structure may benefit from non-structural measures, although from review of available aerial mapping it appears to be an agricultural barn.

In the vicinity of stream mile 6.74 there are three structures potentially affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

The total number of potentially affected structures is 14 based on a count from available aerial mapping.

Liberty Creek

From the mouth of Liberty Creek to stream mile 0.51 there are 23 structures affected by backwater from the Harpeth River during the 1% event. Seven of these structures appear to be in the 10% floodplain. These structures should be evaluated for non-structural applications, but could also benefit from regional detention that effectively lowers peak discharges and flood elevations on the Harpeth River.

In the vicinity of stream mile 0.73 to the upstream extent of study there are three apparently commercial structures and 27 residential structures that are potentially affected by the 1% floodplain. While non-structural measures may be effective for some of the structures, others may be helped by reducing the backwater associated with the stream crossing at Sycamore Drive and a commercial driveway. Map reconnaissance shows that these adjacent crossings cause approximately five feet of head loss from the upstream side where the structures are located to the downstream side of the bridges.

The total number of potentially affected structures is 53 based on a count from available aerial mapping.

Lynnwood Branch

In the vicinity of stream miles 0.66 to 1.11 there are 34 structures potentially affected by the 1% floodplain, 19 of which appear to be in the 10% floodplain, and four of which are repetitive loss structures. Due to apparently shallow flooding these structures may benefit from non-structural measures, although the repetitive loss structures may be scheduled for buy out, and the structures in the 10% floodplain will need further evaluation for depth of flooding.

In the vicinity of stream miles 1.11 to 1.48 there are 17 structures potentially affected by the 1% floodplain, five of which are repetitive loss structures. Due to apparently shallow flooding these structures may benefit from non-structural measures.

In the vicinity of stream miles 1.48 to 1.82 there are two structures potentially affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

The total number of potentially affected structures is 53 based on a count from available aerial mapping.

Mayes Creek

There are no structures that appear to be within the 1% floodplain.

Harpeth River, Tennessee 19 Appendix D May 2012 Appendix D Hydrology & Hydraulics

McCanless Branch

There are no structures that appear to be within the 1% floodplain.

McCrory Creek

In the vicinity of stream mile 0.40 there is one apparently agricultural structure possibly affected by the 1% floodplain.

In the vicinity of stream mile 1.98 there is one apparently agricultural structure possibly affected by the 1% floodplain.

In the vicinity of stream mile 3.69 there are two structures, a home and a shop building, possibly affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

In the vicinity of stream mile 4.12 there are four structures possibly affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

The total number of potentially affected structures is eight based on a count from available aerial mapping.

Overall Creek

In the vicinity of stream mile 1.52 there are two structures, a home and an agricultural building, possibly affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

In the vicinity of stream mile 1.93 there is one structure possibly affected by the 1% floodplain. Due to apparently shallow flooding this structure may benefit from non-structural measures.

The total number of potentially affected structures is three based on a count from available aerial mapping.

Sharps Branch

From the mouth of Sharps Branch to stream mile 0.60 flooding is affected by backwater from the Harpeth River. There appear to be 18 commercial structures affected by the 1% floodplain, one of which is a repetitive loss structure, and of which ten appear to be in the 10% floodplain. There are also seven residential structures potentially affected by the 1% floodplain, six of which appear to be in the 10% floodplain. These structures may benefit from regional detention that lowers flood elevations and discharges along the Harpeth River, or by some combination of regional detention and non-structural measures. Flood depths around the commercial structures appear to range from 2 to 13 feet, and depths appear relatively shallow around the residential structures.

In the vicinity of stream miles 0.60 to 1.15 there are 14 structures that are potentially affected by the 1% floodplain, six of which appear to be in the regulatory floodway based on available mapping overlays. Seven of these structures may be within the 10% floodplain. In this area a combination of floodplain evacuation (buy out) and non-structural measures may be appropriate.

The total number of potentially affected structures is 39 based on a count from available aerial mapping.

Harpeth River, Tennessee 20 Appendix D May 2012 Appendix D Hydrology & Hydraulics

Starnes Creek

In the vicinity of stream mile 2.91 there is one structure possibly affected by the 1% floodplain. Due to apparently shallow flooding this structure may benefit from non-structural measures.

In the vicinity of stream mile 3.56 there are five structures possibly affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

In the vicinity of stream mile 3.70 there are two structures possibly affected by the 1% floodplain. Due to apparently shallow flooding these structures may benefit from non-structural measures.

The total number of potentially affected structures is eight based on a count from available aerial mapping.

Watson Branch

There are no structures that appear to be within the 1% floodplain.

Harpeth River, Tennessee 21 Appendix D May 2012 Appendix D Hydrology & Hydraulics Table 3 - Summary of Map Reconnaissance of the Harpeth Basin above Bellevue, Tennessee Map Reconnaissance, Upstream of Bellevue, Tennessee Stream Vicinity RM 1% Floodplain 10% Floodplain Floodway Measures Considered Description Map Index Total Structures There is a Treatment Plant that appears to be affected by the 77.58 1 1 (also in) Ring Levee/Floodwall/Regional Detention 10 year floodplain. A ring levee or floodwall could protect the Figure 3, #1

Harpeth River Main Stem plant. 14 Commercial and Industrial structures lie within the 100 82.56 14 Nonstructural/Regional Detention Figure 3, #2 year floodplain. 96 Residential structures and 11 commercial or industrial Nonstructual/Flood Warning/Regional 83.93 to 84.09 107 38 (also in) structures are found in the 100 year floodplain. Inundation Figure 3, #3 Detention depths Nonstructural/Evacuation/Regional 86.14 25 3 (also in) 1 Res is Repetitive Loss, Inundation ranges from 6 to 14 feet. Figure 3, #4 Detention There are 7 commercial or industrial structures within the 100 86.55 to 86.77 7 1 (also in) 3 Floodproofing/Regional Detention year floodplain, three of which are affected by the floodway. Figure 3, #5 Flooding depth approximately 8'. 5 structures are repetitive loss and may already be being 87.46 to 88.04 52 12 (also in) Evacuation/Regional Detention Figure 3, #6 evacuated. 88.26 4 Regional Detention Four structures in the 100 year floodplain. Figure 3, #7

25 Structures in the 100 year floodplain. These may benefit Watson Branch to 89.21 25 1 (also in) Nonstructural/Regional Detention Figure 3, #8 from nonstructural measures. Nonstructural/Evacuation/Regional Some of these 6 structures may be eligible for nonstructural 89.38 to 90.03 6 1 (also in) Figure 3, #9 Detention measures. 1 Structure appears to be in the 100 year floodplain and may 95.57 1 Nonstructural/Regional Detention Figure 3, #10 be a candidate for nonstructural measures. Evacuation/Nonstructural/Regional 97.11 5 1 (also in) 3 Agricultural structures and 2 homes Figure 3, #11 Detention Nonstructural/Evacuation/Regional 1 Structure appears to be in the 100 year floodplain and may 99.1 1 Figure 3, #12 Detention be a candidate for nonstructural measures. Nonstructural/Evacuation/Regional Two homes that may be candidates for nonstructural 101.95 2 Figure 3, #13 Detention measures. 105.82 1 Regional Detention Figure 3, #14

Little Harpeth River 2.55 to 3.4 24 7 (also in) Nonstructural/Regional Detention Figure 2, #1

4.94 to 8.34 163 81 (also in) Nonstructural/Regional Detention Figure 2, #2

unavailable 6 Nonstructural/Regional Detention Figure 2

Little Harpeth River Tributary 1 15 Nonstructural Figure 2

Little Harpeth River Tributary 2 5 Nonstructural Figure 2

Little Harpeth River Tributary 3 4 Nonstructural Figure 2

Little Harpeth River Tributaries 4 & 6 77 Nonstructural/Bridge Improvements Figure 2

Little Harpeth River Tributary 5 16 Flood Warning System Figure 2

Little Harpeth River Tributary 7 0.93 2 Nonstructural/Bridge Improvements Figure 2

1.04 6 Nonstructural/Bridge Improvements Figure 2

Little Harpeth River Tributary 8 0.35 2 Nonstructural/Bridge Improvements Figure 2

0.39 4 Nonstructural/Bridge Improvements Figure 2

Little Harpeth River Tributary 10 1.08 2 Nonstructural/Culvert Improvements Figure 2

1.28 2 Nonstructural Figure 2

Little Harpeth River Tributary 11 0.13 1 Nonstructural Figure 2

0.27 3 Nonstructural Figure 2

Harpeth River, Tennessee 22 Appendix D May 2012

Appendix D Hydrology & Hydraulics West Harpeth River 7.03 3 Nonstructural/Regional Detention Figure 3, #15

7.4 3 Nonstructural/Regional Detention Figure 3, #16

8.47 2 Nonstructural/Regional Detention Figure 3, #17

11.01 1 Nonstructural/Regional Detention Figure 3, #18

Murfrees Fork of West Harpeth River 3.84 4 1 Nonstructural/Regional Detention Figure 3, #19

6.75 2 Nonstructural/Regional Detention Figure 3, #20

Arrington Creek Main Stem Figure 3

Arrington Creek Tributary 1 1 Figure 3

Arrington Creek Tributary 2 Figure 3

Arrington Creek Tributary 3 1 Figure 3, #21

Arrington Creek Tributary 4 2 Figure 3, #21

Arrington Creek Tributary 5 Figure 3, #21

Beech Creek 1.72 3 Nonstructural Figure 3

2.39 to 3.62 22 Nonstructural Figure 3

Burke Branch 1.05 2 Nonstructural Figure 3

1.32 2 Nonstructural Figure 3

Cartwright Creek 0.65 12 Nonstructural Figure 3

0.82 1 Nonstructural Figure 3

0.82 to 1.37 16 Nonstructural Figure 3

1.82 16 Nonstructural Figure 3

2.28 2 Nonstructural Figure 3

Leipers Fork Creek 1.68 7 Nonstructural Figure 3

3.08 3 Nonstructural Figure 3

3.8 1 Nonstructural Figure 3

6.74 3 Nonstructural Figure 3

Nonstructural/Regional Detention on Mouth to 0.51 23 Harpeth Backwater at 1% event Figure 3 Liberty Creek Harpeth Nonstructural/Commercial Driveway 0.73 30 Figure 3 Modifications Potentially 0.66 to 1.11 34 19 (also in) 4 are repetitive loss Figure 3 Lynnwood Branch Structural/Nonstructural/Evacuations 1.11 to 1.48 17 Nonstructural 5 are repetitive loss Figure 3

1.48 to 1.82 2 Nonstructural Figure 3

Mayes Creek Figure 3

McCanless Branch Figure 3

McCrory Creek 0.4 1 Figure 3

1.98 1 Figure 3

3.69 2 Nonstructural Figure 3

4.12 4 Nonstructural Figure 3

Overall Creek 1.52 2 Nonstructural Figure 3

1.93 1 Nonstructural Figure 3

Nonstructural/Regional Detention on Mouth to 0.6 25 16 (also in) Harpeth Backwater Figure 3 Sharps Branch Harpeth 0.6 to 1.15 14 7 (also in) 6 Nonstructural/Evacuation Figure 3

Starnes Creek 2.91 1 Nonstructural Figure 3

3.56 5 Nonstructural Figure 3

3.7 2 Nonstructural Figure 3

Watson Branch Figure 3

Harpeth River, Tennessee 23 Appendix D May 2012

Appendix D Hydrology & Hydraulics

Figure 2 – Map Reconnaissance for Locations along the Little Harpeth River, upstream of Bellevue, Tennessee

Harpeth River, Tennessee 24 Appendix D May 2012

Appendix D Hydrology & Hydraulics

Figure 3 - Map Reconnaissance Locations for the Harpeth Basin above Bellevue, Tennessee

Harpeth River, Tennessee 25 Appendix D May 2012

Appendix D Hydrology & Hydraulics

II. Nashville Flood Preparedness

1. Study Area The analyses described in this technical section were conducted as part of the post-flood work on the Harpeth River done in cooperation with the City of Nashville. The results have been used to support the Reconnaissance effort.

The Harpeth River basin lies in Middle Tennessee and drains parts of Rutherford, Williamson, Hickman, Davidson, Dickson and Cheatham Counties. Based on recent Geo-HMS models, the basin drains approximately 865 square miles of Middle Tennessee. The headwaters lie in Rutherford County and the main channel winds downstream to the confluence with the Cumberland River in Cheatham County at Cumberland River Mile 152.9. Major tributaries to the Harpeth River include the West Harpeth River, Little Harpeth River, South Harpeth River, Mayes Creek, Arrington Creek, Turnbull Creek and Jones Creek. From the headwaters to the confluence with the Cumberland River, the Harpeth River falls approximately 450 feet over its roughly 125 mile length. The stream basin is approximately 60 miles long, which, when considered with the stream length, indicates the meandering nature of the river. There are many horseshoe bends in the river, and some are overtopped during extreme flooding. Floodplains along the stream are moderately sloped toward the channel, and the hillsides and ridges are typically forested. Transportation routes cross the basin, and crossroads communities are found at many intersections. There are several densely developed subdivisions located along the river in Davidson and Williamson Counties. Incorporated cities within the basin include parts of Metropolitan Nashville – Davidson County, Franklin, Fairview, Dickson, Kingston Springs, Pegram, Burns, White Bluff and Eagleville. The cities of Dickson and Fairview do not occupy any of the floodplain associated with the main stem of the river. Jones Creek drains the portion of the City of Dickson within the Harpeth River Basin, and a portion of the stream has been studied in detail to establish base flood elevations within the city. Brush Creek and other minor tributaries to Turnbull Creek drain the City of Fairview. Limited portions of Brush Creek have effective base flood elevations.

Land use in the stream basin varies by location. There remains a great deal of open space in the stream basin with hillsides and ridgelines that are forested, and floodplains that are used for agricultural purposes or forested. However, there are pockets of dense development located throughout the basin where land use varies from residential to commercial to industrial. Some of the development has occurred adjacent to the river, while others are located in upland areas that contribute to runoff in the basin. Using GIS estimates of imperviousness in the sub-basins provides a weighted average imperviousness of 10.1% in the Harpeth River Basin. The maximum percentages of imperviousness occur in sub-basins that include Bellevue and Franklin.

2. Historical Flooding

During the week of 02 May 2010 the Harpeth River basin experienced a flood of record for that stream. On 01-02 May, during a 36-hour period historic rainfall fell across portions of Tennessee and Kentucky that produced what can be described as flash flooding on the Cumberland River and its tributaries, including the Harpeth River. Rainfall totals in many areas exceeded 16-inches. The precipitation was estimated to be greater than a 1,000-year rainfall event, and the resultant flooding produced stages of record in many locations throughout the region. High water marks set by Nashville District staff showed the flood to exceed the effective Flood Insurance Study 500-year profile by as much as six feet in some areas along the Harpeth River. There was extensive damage in residential subdivisions that were constructed four feet above the base flood elevation in Davidson County, homes were swept from their

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foundations in Cheatham County, and schools, businesses and public infrastructure were damaged throughout both counties along the Harpeth River. Interstate 40 was inundated by floodwaters and traffic was stopped for a period of time. Many local roads and state highways were also affected by flooding. Damage along the Harpeth River in Williamson County was isolated and not widely reported by local officials.

Floods in Middle Tennessee typically occur in the winter and early spring months. However, depending upon the centering and intensity of a particular storm, floods can occur during any month of the year. Significant flooding on the Harpeth River occurred in 1897, 1902, 1918, 1926, 1929, 1948, 1955, 1956, 1962, 1975, 1990, and 2010. When listed in order of discharge, the four largest floods along the Harpeth River in the Bellevue to Kingston Springs reach are 2010, 1948, 1975, and 1955. The same holds true for the vicinity of the City of Franklin. Below the top four discharges, the order changes between the lower reach and the City of Franklin, probably due to storm centering, intensity, duration and attenuation.

3. Frequency Analysis 3.1. Bulletin 17B Analysis

Several years have passed since the statistical frequency analysis for the gages along the Harpeth River have been updated. The technical work reported in this document was conducted as part of a project with the City of Nashville, and as a result, only the gages at Kingston Springs and Bellevue were analyzed with the updated period of record. The gages at Franklin and above Franklin are also available for use, but have a much shorter period of record than the two used in the Nashville work. The period of record was extended to water year 2010 in order to include the May 2010 flood as part of the analysis of annual peak discharges. This provided a period of record extending from 1926 at Kingston Springs and 1921 at Bellevue. The Nashville District used the HEC-HMS model discussed in the following section, along with a calibrated HEC-RAS model to estimate discharges for the May 2010 flood. USGS published significantly lower discharges for the event based on their rating curves for the gages. The USGS discharges were between the 100- and 500-year FIS discharges in magnitude, but the high water marks for the May 2010 flood were well above the 500-year FIS profile in the study reach. These differences were discussed with the local USGS office, and they are reviewing their rating curves based on information provided them from Corps data and analyses.

The Corps used HEC-SSP 2.0 to perform a Bulletin 17B analysis on the Kingston Springs and Bellevue gages. As a preliminary measure, the analyses were performed using both the USACE and USGS discharges for the May 2010 flood for comparison purposes. When the frequency profiles were computed in HEC-RAS, the frequency discharge values calculated using the USACE flows for May 2010 were adpoted. At the Bellevue gage the adopted skew was 0.218, and the May 2010 event was treated as a high outlier since it far exceeded recorded events. At the Kingston Springs gage the adopted skew was 0.073, and the May 2010 event was treated as a high outlier for the same reason. At both gages, the May 2010 discharges were approximately double the next highest recorded discharge in the period of record. This is plausible when the extent of flooding is considered in connection with historical high water marks. At Franklin the May 2010 flood was 1,000 cfs less than the March 1975 flood, making it the second highest recorded discharge for the period of record spanning 1975-2010. The Harpeth River gage below Franklin has a 21-year period of record (1990-2010), and the May 2010 event is the highest recorded discharge for that gage. The Harpeth River gage at McDaniel has only been in operation since 2007, and so the May 2010 discharge is easily the highest recorded discharge for that gage.

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Table 1 – Statistical Analysis Results Discharge (CFS) Frequency (YR) Bellevue Kingston Springs 1 4,404 5,785 2 12,281 20,274 5 18,549 32,284 10 23,286 41,415 25 29,986 54,326 50 35,535 64,982 100 41,591 76,559 200 48,238 89,189 500 58,052 107,705

4. Hydrology 4.1. Rainfall-Runoff Model Three HEC-HMS runs for the Harpeth River were set up to calibrate to largest observed flows in fairly recent years (outside of May 2010) for which gridded precipitation was available. Grids used were restricted to 2004 and later because of improvements to the quality of gridded precipitation in more recent years. The storms were selected because they had a small wetting prior to the storm, and they represented annual peak storms. The May 2010 storm was not used for calibration because the gages at Bellevue and Kingston Springs were destroyed during the flood that followed. The storms selected were February 2004, May 2009 and March 2004. Geo-HMS was used to collect geospatial data for the drainage basin. A basin file was created for each run in order to maintain the calibration changes in each for comparison. Times of concentration were held constant in all runs and the initial and constant loss rates, storage coefficients, and the base flow recession parameters were varied. The times of concentration were calculated using the three components that were calculated from physical characteristics of the sub-basin flow paths. The storage coefficient (R) was initially set equal to the time of concentration and adjusted as necessary to assist in calibrating the shape of the runoff hydrograph. The computation interval was set at 15 minutes.

Gridded Precipitation and the ModClark transformation method were used in the analysis. The Gridded Precipitation is on an hourly interval. The gridded precipitation had to be offset by 6 hours to calibrate the model due to the offset from GMT. LRN used Base Flow Recession to calculate base flow with discharge per unit area to set up the initial base flow and then set the recession constant and recession ratio. LRN had to lower the base flow (cfs/mi2) in the May 2009 calibration as compared to the February 2004 calibration. Initial and constant loss rates were used to account for soil moisture losses during the storms since the simulations spanned only a few days. The initial losses were 0.3 inches and the constant loss rate ranged from 0.05 to 0.07 inches per hour. Impervious areas were calculated from GIS coverage.

Lag routing was used based on channel length and average velocity, and then adjustments were made for calibration. The Corps attempted to calibrate to the Bellevue and Kingston Springs gages since the Corps was working in the Metro Nashville reach. If the Franklin gage needs to be calibrated to, then Sub-basin 420 in the model will have to be split at the gage location. The Corps was able to achieve a good calibration at both gages for the February 2004 event, with differences of less than 1% in peak

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flows. This was the largest event available for calibration since the Bellevue and Kingston Springs gages were destroyed by the May 2010 flood. The May 2009 flood did not calibrate as well at the Kingston Springs gage. The Corps had to significantly increase the storage coefficient and losses and was still unable to obtain a satisfactory calibration. The Corps noted an anomaly in the observed hydrograph that seemed related to the contribution from Turnbull Creek. If the Turnbull Creek hydrograph was lagged by almost 63 hours, a much better match could be achieved. However, applying this same lag to the February 2004 event produced unacceptable results. One possible explanation in the May 2009 event might be a blockage in the basin, but this seems a little unlikely, and if it is correct, makes the calibration at this gage for this event impossible. The results and final parameters for each run are summarized in the tables below, and the comparison of observed and calculated hydrographs for the Bellevue and Kingston Springs gages are illustrated in the following graphs. The model performed better for larger events because the smaller events are affected more dramatically by depression storage, infiltration, transpiration and other physical phenomena.

The Corps set up, and ran, the 10-, 50- and 100-year storms using the basin model from the February 2004 calibration. Rainfall amounts were taken from the Metro-Nashville Intensity Duration Frequency Curve/Table contained in Volume 2 of the Metro Stormwater Management Manual. The data is given in partial duration, and was put into the HEC-HMS model that way. The Corps changed the transformation method from ModClark to the Clark Unit Hydrograph method, using the same times of concentration and storage coefficients as were used in the calibrated model. The calculated peak discharges at Bellevue and Kingston Springs were compared with the peak discharges reported in the Metro-Nashville Flood Insurance Study published by the Federal Emergency Management Agency. The differences between FIS and calculated values ranged from -1.7% to 20.2%. The calculated values were generally higher in each event at both gages.

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Table 2 – Peak Observed Discharge at Bellevue for Calibrated Events Event Peak Discharge (cfs) February 2004 20,150 May 2009 10,182 March 2004 8,253

Table 2A – FIS and Calculated Discharges at Selected Locations 10-Year 50-Year 100-Year Location (DA) FIS Calc. % Diff. FIS Calc. % Diff. FIS Calc. % Diff. Bellevue (408) 22,300 21,930 -1.7 33,100 34,150 3.2 38,200 39,825 4.3 Conf. w/ South 24,600 28,160 14.5 36,500 43,530 19.3 42,100 50,620 20.2 Harpeth (477) Kingston Springs 38,900 44,480 14.3 57,500 66,570 15.8 65,900 76,790 16.5 (681) Mouth (866) 48,500 55,790 15.0 71,000 84,320 18.8 83,100 97,500 17.3

Table 3 – Calibrated Discharges at Gaged Locations February 2004 May 2009 March 2004 Gage Obs. Calc. % Diff. Obs. Calc. % Diff. Obs. Calc. % Diff. Bellevue 20,150 20,267 0.58 10,182 10,337 1.52 8,253 8,908 7.94 Kingston 24,069 24,284 0.89 13,811 15,281 10.64 9,260 12,057 30.21 Springs

Discharges were computed for the May 2010 flood using gridded precipitation and the calibrated values from the February 2004 model, except that the recession constant and recession ratio that were used were from the March 2004 model. As expected, The Corps’ model performed better at moderate storms than small discharges. Correspondingly, very large magnitude storms will have some small error in the estimate because infiltration loss rates decay as the soils saturate during large events. Infiltration loss may also be affected by storm intensity.

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Harpeth River, Tennessee 33 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Kingston Springs" Results for Run "RevFeb2004"

25,000

20,000

15,000 Flow (CFS)

10,000

5,000

0 3 4 5 6 7 8 9 10 11 12 13 Feb2004 Run:REVFEB2004 Element:KINGSTON SPRINGS Result:Observed Flow Run:REVFEB2004 Element:KINGSTON SPRINGS Result:Outflow Run:REVFEB2004 Element:R80 Result:Outflow Run:REVFEB2004 Element:R100 Result:Outflow Run:REVFEB2004 Element:W330 Result:Outflow Run:REVFEB2004 Element:W320 Result:Outflow

Harpeth River, Tennessee 34 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Bellevue" Results for Run "RevFeb2004"

20,000

15,000

10,000 Flow (CFS)

5,000

0 3 4 5 6 7 8 9 10 11 12 13 Feb2004 Run:REVFEB2004 Element:BELLEVUE Result:Observed Flow Run:REVFEB2004 Element:BELLEVUE Result:Outflow Run:REVFEB2004 Element:R150 Result:Outflow Run:REVFEB2004 Element:W400 Result:Outflow Run:REVFEB2004 Element:W410 Result:Outflow

Harpeth River, Tennessee 35 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Bellevue" Results for Run "Harpeth Revised May 2009" 12,000

10,000

8,000

6,000 Flow (CFS)

4,000

2,000

0 30 1 2 3 4 5 6 7 8 Apr2009 May2009 Run:HARPETH REVISED MAY 2009 Element:BELLEVUE Result:Observed Flow Run:HARPETH REVISED MAY 2009 Element:BELLEVUE Result:Outflow Run:HARPETH REVISED MAY 2009 Element:R150 Result:Outflow Run:HARPETH REVISED MAY 2009 Element:W400 Result:Outflow Run:HARPETH REVISED MAY 2009 Element:W410 Result:Outflow

Harpeth River, Tennessee 36 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Kingston Springs" Results for Run "Harpeth Revised May 2009" 16,000

14,000

12,000

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6,000

4,000

2,000

-0 30 1 2 3 4 5 6 7 8 Apr2009 May2009 Run:HARPETH REVISED MAY 2009 Element:KINGSTON SPRINGS Result:Observed Flow Run:HARPETH REVISED MAY 2009 Element:KINGSTON SPRINGS Result:Outfl ow Run:HARPETH REVISED MAY 2009 Element:R80 Result:Outflow Run:HARPETH REVISED MAY 2009 Element:R100 Result:Outflow Run:HARPETH REVISED MAY 2009 Element:W330 Result:Outflow Run:HARPETH REVISED MAY 2009 Element:W320 Result:Outflow

Harpeth River, Tennessee 37 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Bellevue" Results for Run "Harpeth Revised March 2004" 9,000

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Flow (CFS) 4,000

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2,000

1,000

0 1 2 3 4 5 6 7 8 9 10 11 12 Mar2004 Run:HARPETH REVISED MARCH 2004 Element:BELLEVUE Result:Observed Flow Run:HARPETH REVISED MARCH 2004 Element:BELLEVUE Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:R150 Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:W400 Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:W410 Result:Outflow

Harpeth River, Tennessee 38 Appendix D May 2012 Appendix D Hydrology & Hydraulics Junction "Kingston Springs" Results for Run "Harpeth Revised March 2004" 10,000

9,000

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7,000

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0 1 2 3 4 5 6 7 8 9 10 11 12 Mar2004 Run:HARPETH REVISED MARCH 2004 El ement:KINGSTON SPRINGS Result:Observed Flow Run:HARPETH REVISED MARCH 2004 El ement:KINGSTON SPRINGS Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:R80 Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:R100 Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:W330 Result:Outflow Run:HARPETH REVISED MARCH 2004 Element:W320 Result:Outflow

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5. Hydraulics 5.1. HEC-RAS Steady Flow Model HEC-GeoRAS was used to collect data and display results of our work in this study. An MXD was set up using the DEM “harpstgr20ft” and laid out the sections at the bridges and hydraulic controls, and then added sections to fill in gaps and provide definition at transitions of conveyance. In the final revision cross sections were adjusted to accommodate mapping needs for backwater flooding to the point that new inundation layers converged with FIS mapped inundation of the tributaries. It was noted that the DEM was not very good after crossing the Davidson/Williamson County line into Williamson County. Since the study reach stretched from the mouth to the upstream Davidson County line, the hydraulic model was changed to exclude cross sections in Williamson County because of the DEM. After importing the cross sections in Cheatham and Davidson Counties, they were compared with the effective HEC-2 model cross section geometry that was imported into RAS, the HEC-2 cross sections were used to add definition to the GeoRAS cross sections below the water line. Initial Manning’s coefficients were taken from the HEC-2 model and minor adjustments were made for calibration purposes. Contraction and expansion coefficients were used in accordance with standard practice with few variations. Bridge information was collected from TDOT bridge plans provided by TDOT and input into the model. There were three bridges added to the model that were not in the HEC-2 model (244645-Riverview Drive-PDF 110A3600001; 276850-Newsome Station Road-PDF190D9810005; 313669- Old Harding Road-PDF190D7520001). The plotted FIS profiles were used to pull estimated water surface elevations at the bridges to use as high water marks in the FIS discharge runs in the model. In the final revision of the hydraulic model, a natural high flow cutoff channel was added in the vicinity of the Interstate 40 crossing near the Kingston Springs exit between main channel cross sections 199908 and 225208. This natural cutoff appears to carry flow at the 25-year event and above, and is affected by main channel backwater more frequently on the downstream end.

The hydraulic model was calibrated to three significant historic events in the Harpeth River watershed. The March 1975, February 1989 and May 2010 events were used for model calibration. These are among the largest events to occur in the basin since 1975 and were significant because of the damage that occurred during the floods. LRN used USACE historic high water marks and peak flow data for each flood and calibrated to the high water marks. A reasonable calibration was achieved, particularly to the May 2010 event which had greater density of high water marks. While development in the watershed may have increased imperviousness, and therefore hydrologic response, between 1975 and 2010 there have been few changes that would affect channel hydraulics. Most of these changes would have occurred at bridges, although there may have been isolated locations at which fill was placed in the floodplain.

The Excel files Hydrologic Parameters and High Water Marks were used to aid in model development. The information conveyed below is general information used in the model development and calibration.

• Contraction coefficients varied from 0.1 to 0.3 • Expansion coefficients varied from 0.3 to 0.55 • Manning’s coefficients varied from 0.03 to 0.042 (channel) and 0.075 to 0.09 (floodplain) • Starting water surface elevations were based on the normal depth method with a slope of 0.00016 • Davidson/Williamson County line – near section 328909 • Davidson/Cheatham County line – near section 249613 • USGS Preliminary Estimates of the May 2010 Flood Discharges

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o Bellevue – 46,600 cfs, gage 33.23 (574.27, gage “0” – 541.04) o Kingston Springs – 72,000 cfs, gage 46.00 (493.04, gage “0” – 447.04) o FEMA surveyed HWM at Bellevue – 564.82; at gage – 559.946 (FEMA HWM’s upstream of Bellevue are up and down as you progress upstream.) o The HMS discharges are much higher than the USGS estimates. When the HMS discharges were put into the preliminary RAS model, the profiles were near the USACE HWM’s. The USGS discharges are substantially lower than the USACE HWM’s in a RAS model calibrated to the March 1975 profile. • Effective FIS Discharges Table 4 – Effective FIS Discharges Location 10 50 100 500 Mouth 48,500 71,000 83,100 110,000 Jones Creek 38,900 57,500 65,900 87,100 Kingston Springs Gage 38,900 57,500 65,900 87,100 Turnbull Creek 31,700 46,900 53,900 71,800 South Harpeth 24,600 36,500 42,100 56,600 Bellevue Gage 22,300 33,100 38,200 51,600 Little Harpeth 18,300 27,200 33,000 43,000 Franklin Gage 14,500 21,500 25,000 33,500 Mayes Creek 11,600 17,200 20,000 26,800 Arrington Creek 9,200 13,600 15,800 21,200

• Flow Change Locations for the new model Table 5 – Flow Change Locations in the New Hydraulic Model Location Cross Section River Mile Downstream to Mouth 24116 4.567 Mouth of Jones Creek 53958 10.219 Kingston Springs Gage 171827 32.543 Mouth of South Harpeth 226109 42.824 Bellevue Gage 328008 62.123

• Revised Frequency Discharges Table 6 – Revised Frequency Discharges* Location Cross 10 50 100 500 Section Downstream to Mouth 24116 55,790 84,320 97,500 138,770 Mouth of Jones Creek 53958 54,870 82,830 95,740 136,190 Kingston Springs Gage 171827 44,480 66,570 76,800 108,870 Mouth of South Harpeth 226109 28,160 43,530 50,620 72,900 Bellevue Gage 328008 21,930 34,150 39,830 57,590 *calculated using HEC-HMS

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• Action Levels at the USGS Gages on the Harpeth River (Metro Reach) – Stage (Elev.)

Table 7 – Action Levels at USGS Gages on the Harpeth River – Stage (Elev.) Warning Level Kingston Springs Bellevue Major 30 (477.04) 28 (569.04) Moderate 25 (472.04) 24 (565.04) Flood 20 (467.04) 20 (561.04) Action 18 (465.04) 14 (555.04)

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6. Alternatives Investigated The effort to model alternatives began using the model that was submitted to AECOM for review and incorporation into the FIS update for Metro-Nashville Davidson County. The City of Nashville and their consultant, Barge Waggoner Sumner and Cannon (BWSC), provided a matrix of alternatives to the Unified Flood Preparedness team for consideration. The Nashville District, U.S. Army Corps of Engineers (USACE) was tasked to prepare a cursory screening-level evaluation of the structural alternatives proposed. The sections below provide discussion of the alternatives modeled. The 50-, 100-, 200-, 500-, and May 2010 profiles were modeled for this effort. Harpeth River Miles (HRM) referenced below were provided by the City of Nashville and their consultant, and the corresponding model stations are shown in parentheses beside the HRM. The locations of alternatives discussed are shown in maps contained in the main report.

6.1. Modifications to the I-40 bridge at HRM 53.51 (283650) This alternative was delivered as a simple increase in bridge opening. Nashville did not identify the extents to which the bridge opening was to be increased. USACE assumed an increase of 200 feet toward the left bank. This alternative would require excavation of the left approaches and natural ground on the downstream side of the left approach to create more hydraulic opening, and the installation of piers, beams and decking. The downstream cross section was modified to increase the available conveyance, and at 200 feet increase, the low chord was approximately 7 feet above the ground on the upstream side. There was negligible effect on the 500-year profile, and the profiles for the 200-year event and below were reduced by approximately 0.32 feet. The result of this modification was to decrease the May 2010 profile by approximately 0.68 feet, and effectively converge to the base profile 5.7 miles upstream.

6.2. Modifications to the CSX Bridge at HRM 53.89 (285709) This alternative was not modeled since the proposed revised profiles greatly overtop the bridge for the analyzed discharges.

6.3. Modifications to the CSX Bridge at HRM 56.72 (300809) This alternative was inundated at the 200-year event and above, and caused head losses in all profiles above the 50-year event. The geometry for this bridge was modified by adding 100 feet of bridge opening to each approach (200 feet total), and more modern piers at the locations of the current abutments. This modification lowered the May 2010 profile by 0.16 feet, the 500-year profile by 0.49 feet, the 200-year profile by 0.79 feet, the 100-year profile by 0.72 feet and the 50- year profile by 0.10 feet. The 50-year profile converged to the base profile by the next upstream bridge, while the others effectively converged by the upstream Davidson County line.

6.4. Modifications to the CSX Bridge at HRM 57.88 (307033) This alternative was inundated at the 200-year event and above, and caused head losses in all profiles. The geometry for this bridge was modified by adding 200 feet of bridge opening, and more modern piers to keep the spans relatively short. Structural design may be able to lengthen the spans. Relative low chord and low chord slopes were maintained in the bridge opening. This modification lowered the May 2010 profile by 0.49 feet, the 500-year profile by 0.48 feet, the 200- year profile by 1.10 feet, the 100-year profile by 1.30 feet and the 50-year profile by 2.25 feet. The

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differences converged in minor amounts up to the upper limit of the model at the upstream Davidson County line.

6.5. Modifications to the Old Harding Road Bridge at HRM 59.16 (313669) This alternative was not modeled because the bridge overtops at the 50-year event and above and has limited head loss through the bridge (0.65’+/-). Overtopping occurs in the left approach that would make bridge modifications less effective.

6.6. Modifications to the S.R. 100 Bridge at HRM 61.78 (327938) This alternative may provide some relief to areas outside Davidson County, inside Williamson County, if the bridge opening was increased. The bridge bisects a large bend in the river, and enlarging the bridge opening would subject adjacent fields to more flowing water than might be experienced at this time. Detailed surveys of the bridge superstructure, substructure, approaches and adjacent floodplains could provide better data upon which to base an opinion and conduct more detailed analyses. This alternative was not modeled at this time because the new model stops immediately upstream of the bridge. FEMA may extend the model into Williamson County as part of the FIS update. We recommend further consideration of this alternative for flood damage reduction in Williamson County since the bridge causes significant head losses of up to 0.75 feet for the 5- through 50-year events.

6.7. Cumulative Effects of Modifying Bridges at HRM 53.51, 56.72 and 57.88 These bridges were considered together to determine the effects of modifying all three in unison. The bridge openings were widened similarly to the individual cases noted in the previous discussion. The water surfaces were no different in the combined run for the reach between the bridges at HRMs 53.51 and 56.72. Between HRMs 56.72 and 57.88 the May 2010 profile was lowered by 0.73 feet, the 500-year profile was lowered by 0.64 feet, the 200-year profile was lowered by 1.08 feet, the 100-year profile was lowered by 1.03 feet and the 50-year profile was lowered by 0.23 feet, as compared to the base profile. These differences represent improvements in the water surface profiles in this reach of up to 0.57 feet at the May 2010 event above the single bridge option for this reach. From HRM 57.88 to the upstream terminus of the model the May 2010 profile was lowered by 0.66 feet, the 500-year profile was lowered by 0.97 feet, the 200-year profile was lowered by 1.83 feet, the 100-year profile was lowered by 1.30 feet and the 50-year profile was lowered by 2.37 feet. These differences represent improvements in the water surface profiles in this reach of up to 0.73 feet at the 200-year event above the single bridge option in this reach. It seems that the best results are provided by modifying all three bridges as opposed to individual bridges.

6.8. Diversion Channel Cutting Off the Bend Between HRMs 57.99 and 56.72 This alternative was suggested by the Metro-Nashville consultant, and USACE prepared a cursory analysis for screening purposes. The proposed alternative includes the construction of approximately 3,000 linear feet of diversion channel that is twenty feet wide at the bottom, five feet deep and has 3:1 side slopes. The diversion channel was designed with the bottom below the 2-year water surface profile elevation and the effects on the 50-year through May 2010 profiles were analyzed. Based on the preliminary HEC-RAS analysis, it appears that this alternative has the potential to lower the water surface profiles immediately upstream of the cutoff channel by amounts ranging from 2.0 feet during the May 2010 event to 3.9 feet during the 50-year event, with the other frequency events ranging between those values. At the upper end of the study reach the

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values ranged from 0.91 feet to 1.3 feet for the same events. This alternative shows some promise, but should be developed in detail and the hydrologic routing taken into account to ensure conditions are not changed downstream.

6.9. Levees at HRM 58.2 (307103) This alternative, discussed earlier in this Appendix, was identified by BWSC for the Metro Unified Flood Preparedness team as having potential for flood damage mitigation for homes on the right bank of the Harpeth River at this location. The option included 6,000 linear feet of levee and a pump station to remove interior drainage. USACE included the levee in a geometry data set for the HEC-RAS model to determine the effects of the alternative on natural flood profiles. This option caused an increase of 0.15 feet during a recurrence of the May 2010 event, an increase of 0.12 feet for the 200-year event, and did not affect lesser events. The levee alternative caused an increase of up to 0.21 feet per second in velocities in the study reach, and did not appear to have additive effects on the levee alternative at HRM 60.3.

6.10. Levees at HRM 60.3 (318385) This alternative, discussed earlier in this Appendix, was identified by BWSC for the Metro Unified Flood Preparedness team as having potential for flood damage mitigation for homes on the right bank of the Harpeth River at this location. The option included 5,800 linear feet of levee and a pump station to remove interior drainage. USACE included the levee in a geometry data set for the HEC-RAS model to determine the effects of the alternative on natural flood profiles. This option caused an increase (0.03 feet) during the 100-year discharge, and larger increases for events up to the recurrence of the May 2010 event, which had a maximum increase of 0.15 feet. It should be noted that since this alternative is very near the upstream end of the model, and thus the county line, that effects beyond this limit are not quantified. Events lower than the 50-year discharge were unaffected by the alternative.

6.11. Dry Reservoir at the Lumpkins Bridge Road area in Williamson County This alternative was given a cursory evaluation using HEC-HMS by modifying the model calibrated and used to develop frequency discharges for the HEC-RAS model used for the Unified Flood Preparedness project. USACE evaluated the proposal using elevation-storage data provided by BWSC, and controlling the outlet to obtain a maximum pool elevation while allowing just over 3 feet of freeboard to remain. Storage information was given in acre-feet for elevations 690 (19,640) and 700 (44,760). The results of the HMS analysis show that this alternative has promise for significant reduction of discharges through the City of Franklin and parts of Williamson County, but that the reductions in discharge drop to 5.9% for the 100-year event at the Bellevue gage. At the Kingston Springs gage the discharges converge to without-reservoir magnitudes. In the Franklin reach, 100- year discharges were reduced by approximately 90% in the preliminary analysis. Since the reductions were realized in the reach above the HEC-RAS model terminus, no HEC-RAS runs were done to develop inundation and depth grids.

Harpeth River, Tennessee 46 Appendix D May 2012

Appendix E

Hazardous, Toxic & Radioactive Waste

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Appendix E Hazardous, Toxic & Radioactive Waste U.S. EPA Federally Listed Sites A U.S. EPA database search was conducted on 15 September 2011 for Dickson County , Williamson County, Southwest Davidson County and West Rutherford County. Databases searched included Resource Conservation and Recovery Act Information database (RCRAINfo), Brownfields database (ACRES), Comprehensive Environmental Response, Compensation and Liability Information System (CERCLIS), Permit Compliance System (PCS), Radiation Information (RADINfo), Toxic Release Information (TRI), and Toxic Substance Control Act database (TSCA).

The website with the multiple federal environmental databases is http://www.epa.gov/ enviro/index.html and the databases summary results are attached to this memo.

The results of this search are the facilities that are registered with U.S. EPA in the realm of RCRA, Brownfields, CERCLA, NPDES, Radiation, Toxic Release and TSCA. The facilities listed in RCRAInfo and NPDES may be in compliance without violation, had a violation(s) and now is in compliance, or have current violation. Sites listed under CERCLIS may be in a wide range of statuses including no further action and site is closed, action completed, or further action. TRI registered sites may be in remediation or remediation complete status. There are no sites registered under the ACRES, RADINfo or TSCSA realms in the areas searched.

This appendix summarizes all U.S. EPA listed sites in the 5 databases searched. Not all the facilities are in an area to impact the Harpeth Watershed, and not all facilities have had a release that may affect the Harpeth Watershed. For future work, when potential project sites are identified within the watershed, a narrowed radius search around the project site should be conducted to determine if any of the listed sites may have impacted the project site.

Table 1 - Summary of US EPA listed sites by county or zip code.

Type of Facility/Site Number of Sites per County or Zip Code Davidson Dickson Rutherford Williamson 37221 County 37060 County ACRES – Brownfields 0 0 0 0 CERCLIS – Superfund (listed and not listed) 0 4 0 2 PCS – Permit Compliance System – NPDES 1 11 0 20 RCRA – Resource Conservation and Recovery Act 22 63 4 207

TRI – Toxic Release Inventory Form R 0 16 0 18 TSCA – Toxic Substance Control Act 0 0 0 0 Results are from a multisystem search on the U.S. EPA Envirofacts database on 15 Sep 2011 Note: all of Dickson and Williamson Counties were searched. Only one zip code in Davidson and Rutherford Counties were searched. Note: Some facilities may be listed in multiple directories. For example, in Davidson 37221, one of the RCRA sites also includes an NPDES permit, so there were 22 sites identified, with 23 entries in the multi-system search.

Harpeth River, Tennessee 1 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste Davidson County Only zip code 37221, southwest Davidson County, was searched in the federal environmental databases. 22 federally registered facilities were identified.

Of the 22 facilities, 20 are registered in RCRAInfo. Of the 20 RCRA facilities, 5 are registered as small quantity generators, and 5 are registered as conditionally exempt small quantity generators.

There are no facilities registered with radiation or radioactivity.

There are no facilities registered with uncontrolled toxic release.

There are no registered brownfields.

There is 1 federally registered National Pollution Discharge Elimination System (NPDES) permit for the Harpeth Valley Utility District.

Dickson County There are 89 facilities which are registered in at least one federal environmental database.

There are no facilities registered with radiation or radioactivity.

There are no registered brownfields.

16 facilities have registered at least one toxic release in the history of the facility. A toxic release may be remediated, and the facility may be in compliance.

There are 11 facilities with NPDES permits. 10 facilities which are categorized as non-major dischargers and one facility is a major discharger. One of the non-major dischargers is the USACE Cheatham Power Plant.

There are 63 facilities which are registered in RCRAInfo. The facilities are either a generator, transporter, treater, storer or disposer of hazardous waste. Five facilities are large quantity generators; 14 are conditional exempt small quantity generator; and 14 are small quantity generators. USACE Cheatham Power Plant is one of the conditionally exempt small quantity generators.

There are four facilities registered in the CERCLIS. These facilities are closed or abandoned sites that were assessed for hazardous waste for consideration to be placed on the National Priority List (NPL). Most facilities investigated for consideration for the NPL are not placed on the NPL, but remain listed on CERCLIS to indicate that an initial investigation took place. The Dickson County Landfill on Eno Road, Dickson, TN was discovered in 1986 and is not on the NPL. The site was archived in 1993, and unarchived in 2003. In 2006, the responsible party declared bankruptcy. Luther Lake Contamination is listed on CERCLIS, but not an NPL site. The responsible party performed a removal action in 2001, and the status of the site is “stabilized”. Scoville Schrader Automotive on Schrader Lane, Dickson, TN is listed on CERCLIS, but not an NPL site. The site was discovered in 1980, and the EPA reassessment was completed in 2010 indicating the site shall have a higher priority for re-assessment. Swift Thermometer

Harpeth River, Tennessee 2 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

on Summerfall Road, Dickson, TN is registered in CERCLIS, but not an NPL site. There was a removal action in 2006. The most current action was cost recovery which was completed in 2009.

Rutherford County Only zip code 37060, Eagleville and surrounding area, was searched in the federal environmental databases. 4 federally registered facilities were identified.

There are 4 facilities registered in the Resource Conservation and Recovery Act Information (RCRAInfo) database. The facilities are either a generator, transporter, treater, storer or disposer of hazardous waste.

There are no facilities registered with radiation or radioactivity.

There are no facilities registered with uncontrolled toxic release.

There are no registered brownfields.

Williamson County There are 237 facilities which are registered in at least one federal environmental database.

There are no facilities registered with radiation or radioactivity.

There are no registered brownfields.

18 facilities have registered at least one toxic release in the history of the facility. A toxic release may be remediated, and the facility may be in compliance.

There are 20 facilities with NPDES permits. 16 facilities which are categorized as non-major dischargers and one facility is a major discharger.

There are 207 facilities which are registered in RCRAInfo. The facilities are either a generator, transporter, treater, storer or disposer of hazardous waste. Five facilities are large quantity generators; one is a treatment, disposal, or storage facility; 45 are conditional exempt small quantity generators; 45 are small quantity generators; and two are transporters.

There are two facilities registered in the CERCLIS. Franklin Battery Chip Site, located Mallory Station Road and Seaboard Lane in Franklin, TN was assessed and did not qualify for NPL status and the site was archived in CERCLIS in 2005, but unarchived in 2008 with no further CERCLIS status listed. College Grove Battery Chip Site, located at Arno College Grove and Horton Road in College Grove, TN, was assessed and is not listed on the NPL. The site has registered three removal actions completed in 2004, 2006, and 2010.

Harpeth River, Tennessee 3 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste National Response Center The National Response Center (NRC) is a part of the U.S. Coast Guard, and is the sole federal point of contact for reporting oil and chemical spills in all media including water, soil and air. The NRC database includes reported incidents from 1982 to present.

The website with the NRC database is http://www.nrc.uscg.mil/nrchp.html and the NRC database results are attached to this memo.

Record searches for Dickson and Williamson Counties were conducted for 2009 to present (21 Sept 2011 the date of the NRC record search). A spill or release may include oil, other liquids, solid and gases released to the environmental media. The spills or releases may or may not impact the Harpeth Watershed. For example, if there an incident where used concrete building material illegally dumped, is not near the Harpeth River or tributaries, and the material has been removed and disposed of properly, it is unlikely the material poses a threat to the watershed. This report lists all the NRC registered incidents in Dickson and Williamson Counties is 2009 to present regardless of potential impact to the Harpeth River Watershed. For future work, when potential project sites are identified within the watershed, a narrowed radius search around the project site should be conducted, and possibly a longer historical duration than 2.75 years, to determine if there have been any NRC reported incidents within proximity to the project site.

Davidson and Rutherford Counties were not searched because there is only a small portion of each county that are within the Harpeth River Watershed, and likely the reported releases and spills incidents would not be applicable to the Watershed. If any project sites are identified in either of these two counties, it is recommended that a NRC search be conducted for the area.

Dickson County There were 8 incidents reported between 1 January 2009 to present. There were no reported releases in 2009. There were four spills or releases to land in 2010 including diesel, waste oil and toluene. There were four spills or releases reported in 2011, one diesel spill on I-40 at mile marker 172, one used oil spill on Center Street, and two releases to surface water. The first surface water release was discovered on 27 June 2011 which water and hydraulic fluid was released into a storm drain that connects to Crab Creek, and the release was from Nemak on Old Columbia Road, Dickson, TN. The second surface water release was reported on 15 August 2011, was about a 150 gallon diesel fuel release on HWY 70 West into a creek nearby, and the release was from a Dart tractor trailer accident. It is possible that the two releases to water have directly impacted the Harpeth Watershed.

Williamson County There were 8 incidents reported between 1 January 2009 to present. There was one incident reported in 2009 near 8401 Horton HWY, College Grove, TN. The incident appeared to be dumping of tires, cross ties, diesel fuel, sheet rock and trash on to land then using back hoes to bury the material. In 2010 there was one diesel spill on land at the Flying J gas station on HWY 96 in Fairview, TN. In 2011 there were six spills or releases reported. There were two releases to air one of anhydrous ammonia and the other of an unknown substance. One release was a freight car fire in Brentwood, TN. One incident was reported

Harpeth River, Tennessee 4 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

and classified as a non-release on HWY 840 in College Grove, TN because it was a fully encapsulated container of rock cocaine that did not cause a release to the environment. One incident was a private property barn fire which included shot gun shells, propane, welding rods and a liquefied oxygen tank located on Old Hillsboro Pike in Franklin, TN. The last reported incident was regarding an individual being arrested on City Center Way in Fairview, TN holding an open container with an oily substance in it.

Tennessee State Listed Sites Tennessee Department of Environmental Conservation (TDEC) regulates and permits a wide variety of facilities to protect the air, land and water of TN. TDEC regulated sites, if they were to have an uncontrolled release of hazardous materials or waste, such as solid waste and landfill facilities, industrial outfalls, and underground storage tanks, could affect the Harpeth River Watershed. Readily available TDEC database searches are summarized below.

TDEC Permitted Landfills TDEC Solid Waste Management (SWM) Division regulates and permits solid waste handling facilities, and is categorized by county. The most up-to-date solid waste facility list for TN is from 26 August 2010 and is available from the TDEC SWM website http://tn.gov/environment/swm.

All registered TDEC SWM sites were counted in each county, and not by zip code in Davidson and Rutherford counties. It is likely the majority of listed SWM facilities in Davidson and Rutherford Counties are not within the Harpeth River Watershed, but all facilities in each of these counties were counted. The listed sites may or may not be in the Harpeth River Watershed, and may or may not be in compliance. For future work, when potential project sites are identified within the watershed, a narrowed radius search around the project site should be conducted to determine if any of the listed sites may have impacted the project site.

Table 2 - Summary of TDEC Solid Waste Management Sites by County.

Waste Unit Type Davidson Dickson Rutherford Williamson County County County County Coal Ash 0 0 0 0 Land Application 0 0 0 0 Transfer Station 5 (2 closed) 0 0 3 (1 closed) Processing, tire 49 (32 closed) 2 (1 closed) 9 (7 closed) 3 (1 closed) storage, composting Convenience 5 (2 closed) 10 15 (1 in Eagleville) 9 Class IV 2 (1 closed) 1 1 (1 closed) 0 construction and demolition waste Class III farming, 1 0 1 1 landscaping, land clearing waste Class II industrial 6 (3 closed, 1 (1 closed) 0 0

Harpeth River, Tennessee 5 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

waste 3 post closure) Class I municipal 2 (1 closed, 1 (1 post closure) 2 (1 post closure) 1 (1 closed) solid waste 1 post closure) As of 826 August 2010 TDEC SWM http://tn.gov/environment/swm/ Note: #a (#b closed) – there are “a” number of SWM facilities in the county with “b” number of those “a” count that are closed. Note: 15(1 in Eagleville) – there are 15 listed convenience centers in Rutherford County, but only one of them is in the Eagleville area which is known to be in the Harpeth River Watershed

TDEC Permitted Industrial Outfalls TDEC issued a Water Quality Management Plan (TDEC, Nov 2000) listing the various permitted outfalls as of November 2000 in the Harpeth River Watershed. It is possible that some outfalls are closed and there are new permitted outfalls since 2000. When project sites are identified, outfalls near each project site should be identified. Until specific project sites are identified in the Harpeth River Watershed, it is unknown if any of the TDEC registered outfalls are in the proximity of a project site, or if any of the outfalls may impact a project site. The TDEC registered outfalls are summarized in the table below. Table 3 - Summary of TDEC registered outfalls in the Harpeth River Watershed.

SUB FACILITY FACILITY WATERSHE NUMBER NAME SIC SIC NAME MADI WATERBODY D College Grove Unnamed trib @0.7 to TN0067164 ES 4952 Sewerage Systems Minor Overall Creek @ mi 0.8 5130204010 Unnamed trib @0.46 to Rutherford Creek@ mi TN0064475 Bethesda ES 4952 Sewerage Systems Minor 27.9 5130204010 General Primary Smelting Smelting and and refining of Harpeth River @ mi TN0001384 Refining 3339 Nonferrous Metals Major 110.3 5130204010 Eagleville Cheatham Branch@ mi TN0057789 School 4952 Sewerage Systems Minor 1.9 5130204010 Elementary and Unnamed Trib to Five TN0067873 Oakview ES 8211 Secondary Schools Minor Mile Creek @ mi 1.1 5130204020 Franklin STP Best Western- Harpeth River @ mi TN0028827 Goose 4952 Sewerage Systems Major 85.2 5130204020 Creek Inn STP Williamson Five Mile Creek @ mi TN0060216 County 4952 Sewerage Systems Minor 2.2 5130204020 Crushed and Broken TN0068861 Hwy Dept 1422 Limestone Minor Trib to Harpeth River 5130204020 Trinity ES Unnamed trib @ mi 0.4 Nashville to Mayes Creek @ mi TN0064297 South 4952 Sewerage Systems Minor 1.7 5130204020

Harpeth River, Tennessee 6 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

Auto/Truck Except with Surface Ditch to Five TN0073580 Plaza 5541 Convenience Stores Minor Mile Creek @ mi 2.2 5130204020 Page MS Harpeth Valley Hapeth River @ mi TN0057835 Utility 4952 Sewerage Systems Minor 101.9 5130204020 District STP Cartwright Harpeth River @ mi TN0025232 Creek 4952 Sewerage Systems Major 57.8 5130204030 U.C. STP Lynnwood Harpeth RIver @ mi TN0027278 Utility Corp. 4952 Sewerage Systems Minor 68.8 5130204030 Table Continued SUB FACILITY FACILITY WATERSHE NUMBER NAME SIC SIC NAME MADI WATERBODY D Harpeth RIver @ mi TN0029718 STP 4952 Sewerage Systems Minor 77.9 5130204030 Hutton Stone, crushed and broken TN0066672 Inc. 1422 Limestone Minor Harpeth River 5130204030 Delta Express Processed TN0068489 #3217 5441 Wastewater Minor Tributary of Flat Creek 5130204030 Pegram STP Harpeth Valley Harpeth RIver @Mile TN0074586 Utility 4952 Sewerage Systems Minor 46.0 5130204030 District STP Cartwright Harpeth River@ mi TN0025232 Creek 4952 Sewerage Systems Major 57.8 5130204040 U.C. STP Lynnwood Harpeth River@ mi TN0027278 Utility 4952 Sewerage Systems Minor 68.8 5130204040 Harpeth RIver@ mi TN0029718 Corp. STP 4952 Sewerage Systems Minor 77.9 5130204040 Pinewood Branch @ mi 0.1 to Wilkie Branch @ TN0057827 Hillsboro ES 4942 Sewerage Systems Minor mi 0.5 5130204040 Harpeth RIver @ Mile TN0074586 Pegram STP 4952 Sewerage Systems Minor 46.0 5130204040 Kingston Springs STP Harpeth River@ mi TN0059790 Second South 4952 Sewerage Systems Minor 31.5 5130204070 Harpeth River @ mi TN0004294 Cheatham UD 4941 Water Supply Minor 36.1 5130204070 White Bluff STP Interstate TN0020460 Packaging 4952 Sewerage Systems Minor Trace Creek @ mi 4.3 5130204070

Harpeth River, Tennessee 7 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

Non Contact Cooling Wet Weather Conv. TN0068675 Corporation 2671 Water Minor intoFlat Creek@ mi 3.1 5130204070 Fairview STP Bethany Hills Flatrock Branch @ mi TN0062332 Camp 4952 Sewerage Systems Minor 2.15 5130204070 Sullivan's Branch @ mi TN0028991 STP 4952 Sewerage Systems Minor 1.8 5130204080 Stuart Burns Beaver Dam Creek @ TN0063878 ES 6211 Other Minor mi 3.7 5130204080 Unnamed Trib to Saltire Willow Branch of Piney TN0074659 Industrial Minor River 5130204080 Dickson Motel TN0057002 STP 4952 Sewerage Systems Minor Gin Branch@ mi 3.0 5130204080 Turnbull UD- TN0004855 Burns 4941 Water Supply Minor Turnbull Creek 5130204080 TN0066958 Dickson STP 4952 Sewerage Systems Major Jones Creek@Mile 21.7 5130204090 Note: the table is from Appendix IV of the Water Quality Management Plan, TDEC 2000, and labeled Table A4-5. Active Permitted Point Source Facilities in the Harpeth River Watershed. Note: STP=sewage treatment plant Note: SIC=Standard Industrial Classification; MADI=Major Discharge Indicator; UD=Utility District.

TDEC Permitted Mines TDEC has permitted 4 mines as of 2000 in the Harpeth River Watershed, and as reported in Appendix IV of the Water Quality Management Plan (TDEC, 2000). Until specific project sites are identified in the Harpeth River Watershed, it is unknown if any of the TDEC registered mines are in the proximity of a project site, or if any of the mines may impact a project site. The four mines are summarized in the table below. Table 4 - Summary of TDEC permitted mines in the Harpeth River Watershed.

FACILITY NUMBER FACILITY NAME SIC SIC NAME WATERBODY HUC-11 Williamson Crushed and Trib to Harpeth TN0068861 County Quarry 1422 Broken Limestone River 5130204020 Wet Weather Crushed and Conveyance to TN0027774 Franklin Quarry 1422 Broken Limestone Carters Creek 5130204020 Hutton Stone Crushed and TN0066672 Quarry 1422 Broken Limestone Harpeth River 5130204030 Crushed and TN0002747 Dickson Quarry 1422 Broken Limestone Jones Creek 5130204090 Note: the table is from Appendix IV of the Water Quality Management Plan, TDEC 2000, and labeled Table A4-6. Active Mining Sites in Harpeth River Watershed in the plan

Harpeth River, Tennessee 8 Appendix E May 2012 Appendix E Hazardous, Toxic & Radioactive Waste

Reference: TDEC, Nov 2000. Harpeth River Watershed (05130204) of the Cumberland River Basin, Water Quality Management Plan. Tennessee Department of Environment and Conservation Division of Water Pollution Control Watershed Management Section, November 9, 2000.

TDEC Registered USTs TDEC Division of Underground Storage Tanks (USTs) maintains a database of all TN registered USTs and other pertinent information about the USTs such as age, type, size, closure, owners, contact information etc. Each record may be purchased for $0.10. More information about obtaining UST information may be found at the TDEC Division of USTs website http://tn.gov/environment/ust/reg_data.shtml#database. At this time, it is unknown how many USTs are within Davidson, Dickson, Rutherford and Williamson Counties, and which USTs are within the Harpeth River Watershed. USTs should be identified within a 0.5 mile radius of each project site when project sites within the Harpeth River Watershed are identified.

Local, Tribal and Other Listed Sites Local, tribal and other environmental listed sites were not searched at this time. When specific project sites are identified for the Little River Watershed, a search for local, tribal and other environmental listed sites within the proximity of the project site should be conducted. A site reconnaissance should also be conducted to confirm each listed site and potential for illegal or not previously identified environmental sites that may impact a project site.

Harpeth River, Tennessee 9 Appendix E May 2012

Appendix F

References

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Appendix F References

Ahlstedt, Steven. U.S. Geological Survey. 2002. Harpeth River Mussel Survey.

Harpeth River Watershed Association. 2001. Volunteer Site-Specific Visual Stream Assessment of 303(d)/305(b) Listed Streams in the Harpeth River Watershed.

Harpeth River Watershed Association. Dissolved Oxygen Study Charts 2006, 2007, 2008.

Harpeth River Watershed Association. 2007. Volunteer Stream Bank Erosion Study “So How Much Sediment Does Bank Erosion Generate?" http://www.harpethriver.org/library/library?id=55414.

Harpeth River Watershed Association. 2009. Impervious Area Analysis for the Harpeth River Watershed Based on Analysis of 1997 and 2007 Ortho Photos and Local Parcel Maps and Compared to Cumberland Region Tomorrow’s 2001 Projections for 2020.

Harpeth River Watershed Association. 2011. March 2011 Newsletter. Voices of the Harpeth. http://www.harpethriver.org/library/library?id=75193.

Harpeth River Watershed Association. 2011. Lowhead Dam Removal and River Restoration Project on Harpeth River in Franklin. http://www.harpethriver.org/program/lowhead_dam.

Hubbs, D., Ahlstedt, S. 2002. Mussel Collections on the Harpeth River between College Grove in Rutherford County and Collier’s Bend in Dickson County.

Pennington & Associates. 2006. Fish and Macroinvertebrate Surveys Harpeth River, City of Franklin Williamson County, Tennessee.

Rakes et al. 1998. Aquatic Fauna Survey and Baseline Fish Status Survey of Kelley Creek, Williamson County, Tennessee. http://www.sitemason.com/files/aVB3dS/Aquatic%20Fauna%20Survey%20of%20Kelley %20Creek%201998.pdf.

Russell et al. 2005. A new species of “Lithasia” (Mollusca: Caenogastropoda: Pleuroceridae) from the Harpeth River, Tennessee, U.S.A. Zootaxa 1054:31-42.

Tennessee Department of Environment and Conservation. 2000. Harpeth River Watershed (05130204) of the Cumberland River Basin: Water Quality Management Plan. http://tn.gov/environment/watersheds/one/harpeth/.

Tennessee Department of Environment and Conservation. 2009. Tennessee Natural Heritage Program Rare Species Observations for U.S. Geological Survey 8 Digit Hydrologic Unit Code Watersheds.

Tennessee Department of Environment and Conservation. 2009. A Guide to the Rare Animals of Tennessee.

Harpeth River, Tennessee 1 Appendix F May 2012 Appendix F References

Tennessee Department of Environment and Conservation. 2010. EPA approved 303(d) list. Tennessee Department of Environment and Conservation Division of Water Pollution Control. 2010. 2010 305(b) Report: The Status of Water Quality in Tennessee.

Tennessee State Parks. 2012. http://tn.gov/environment/parks/.

Tennessee Wildlife Resources Agency. 2002.

Tennessee Wildlife Resources Agency. 2011. Fish Community Assessment In The Harpeth River Prior To The Removal Of The Dam At Franklin, TN.

Tennessee Wildlife Resources Agency. 2012. http://www.tn.gov/twra/.

The Tennessean. 2011. Historic Flood Gives New Life to TN’s Streams. http://www.tennessean.com/article/20111224/NEWS11/312240013/Historic-flood-gives- new-life-to-TN-s-streams.

TRC, Inc. 2007. Data Recovery at 40CH195, The Harpeth Shoals Marina Site, Cheatham County, Tennessee.

U.S. Army Corps of Engineers. 2010. After Action Report.

U.S. Army Corps of Engineers. 1991. Final Detailed Project Report and Environmental Assessment: Section 205, Flood Damage Reduction. Little Harpeth River Williamson County, Tennessee.

U.S. Army Corps of Engineers. 1990. Harpeth River I-840 Study.

U.S. Census Bureau. 2011. http://www.census.gov/.

U.S. Department of Agriculture. 2011. Economic Research Service: County-Level Population Data for Tennessee: Percent Change in Population, 2000-10. http://www.ers.usda.gov/Data/Population/PopList.asp?longname=Tennessee&st=TN&so rtBy=pctCountyChange20002010&sortMsg=population+change+2000- 2010&sortColumn=7&priorSortBy=pctCountyChange20002010#table.

U.S. Environmental Protection Agency. 1997. Ecoregions of Tennessee. EPA/600/R-97/022.

U.S. Fish and Wildlife Service. 1984. Tan Riffle Shell Pearly Mussel Recovery Plan. U.S. Fish and Wildlife Service, Atlanta, Georgia. 59pp.

U.S. Global Research Program. 2009. Global Climate Change Impacts in the United States. New York, NY: Cambridge University Press.

Harpeth River, Tennessee 2 Appendix F May 2012 Appendix F References

U.S. Government Accountability Office. 2007. Climate Change: Agencies Should Develop Guidance for Addressing the Effects on Federal Lands and Water Resources. Report to Congressional Requestors. Washington, DC: USAGO.

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