chapter 7: little hatchet creek 7.1 introduction the little hatchet

Chapter 7: Little Hatchet Creek Draft 10/24/02

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7.1 Introduction The Little Hatchet Creek watershed is lo-cated in the northeastern quadrant of the city of Gainesville (Figure 7.1). Little Hatchet Creek flows from west to east and empties into Newnans Lake.

The watershed of Little Hatchet Creek is

Figure 7.2 Little Hatchet Creek Watershed

Figure 7.1 Location of Little Hatchet Creek watershed in Alachua County

The basin is comprised of four sub-basins that collectively encompass 51 square miles of urban and rural Gainesville: An unnamed drain that includes the Ironwood Golf Course area, Airport Basin, Gum Root Swamp Basin and Prairie Creek Reach, which surrounds Newnans Lake (Figure 7.2). Land surface elevation above NGVD ranges from 165 feet in the upper part of the watershed to 70 feet near Newnans Lake. The majority of the watershed is located in the Northern Highlands physiographic province (White 1970). Land surface elevations decrease as Little Hatchet Creek crosses the Cody Scarp (toe at 100 feet above NGVD) into the Central Highlands physiographic province on the north side of Newnans Lake (White 1970; Hoenstine and Lane 1991). A thin mantle of Plio-Pleistocene terrace deposits of


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sands, silts and clays overlies the entire watershed. Beneath these surface deposits, along the creek banks and bed are outcrops of the Hawthorn Group (Spangler 1985). These outcrops are easily observed as the elevation decreases, downstream of Waldo Road (SR 24). Biological communities in the watershed consist of pine flatwoods, bald cypress swamps and mixed hardwood hammocks. Soils in the majority of Little Hatchet Creek watershed are somewhat poorly drained and sandy to a depth of 40-80 inches. A small area of the watershed in the vicinity of Gum Root Swamp Conservation Area has soils that are very poorly drained (Thomas et al 1985). Residential, commercial, and institutional land uses dominate in the western areas of the watershed. Single family homes and most local businesses are located west of SR 24 between NE 39th Avenue (SR 222) and NE 16th Avenue. Located close to the headwaters of Little Hatchet Creek is the Murphree Wellfield and Water Treatment Plant, where groundwater is pumped from the Floridan aquifer to supply the drinking water needs of Gainesville. Gainesville Regional Utilities operates the plant and owns 7100 acres of the surrounding area as a conservation easement. Located in the northern portion of the watershed are the Alachua County Animal Services facility, the Alachua Solid Waste Transfer Station, and the Alachua County Household Hazardous Waste Collections Center. Other properties include the Gainesville Regional Airport located on SR 222 and multiple small businesses such as automobile and appliance repair shops and furniture refinishers, located in industrial parks along Waldo Road.

Schools in the area include Howard Bishop Middle School, Metcalf Elementary School, a One-Room Charter Schoolhouse and St. Patrick’s School. Several State facilities are located in the area around SR 222, including Santa Fe Community Correctional Center, Gainesville Correctional Institution, Alachua County Sheriffs Office, Alachua County Correctional Center Department of the Jail, and North Florida Juvenile Detention Center. Ironwood Golf Course, Gum Root Park and Gum Root Swamp Conservation Area are located in the southern and eastern parts of the watershed and are used for recreation in the form of golfing and hiking. Ironwood Golf Course is an award-winning course that has won many awards for its natural community conservation and environmental awareness. In 1999, it became one of the first municipal golf courses in Florida to be certified by Audubon International, a group that grades courses based on wildlife habitat, water conservation and pesticide use (USGA 2002). Gum Root Park and Gum Root Swamp Conservation Area encompass 741 acres of forested wetlands

Ironwood.Golf Course


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7.2 Watershed Description Little Hatchet Creek consists of a number of intermittent natural tributaries, dredged canals, and swamps. The sections of the creek that are dredged or channelized tend to flow more consistently than the natural, more swampy sections, many of which are dry except during periods of high flow. Much of Little Hatchet Creek’s baseflow is from springs and seeps that emerge in dredged ditches and canals along the creek’s southwestern portion in Unnamed and Airport Basins. An area of pine flat-woods northeast of NE 39th Avenue serves as a sheetflow area that drains both to the creek and to Newnans Lake. Gum Root Swamp also contributes baseflow to the creek as Little Hatchet Creek flows through the swamp before emptying into Newnans Lake. The main channel of Lit-tle Hatchet Creek begins from a 24-inch corrugated metal pipe in the vicinity of NE 53rd Avenue and flows east to Brittany Es-tates subdivision. A tributary of Little Hatchet Creek, Lateral A, begins near NE 9th Street and flows northeast to join the main channel at the eastern edge of Brit-tany Estates. The main channel of Little Hatchet Creek continues east and then southeast through

the Airport Industrial Park after which it flows through Gum Root Swamp Conser-vation Area and empties into the northern portion of Newnans Lake. Main tributaries of Little Hatchet Creek include a tributary located on Ironwood Golf Course and the Airport Basin tribu-tary (Figure 7.2). Ironwood tributary flows east to meet the southern branch of Little Hatchet Creek just north of NE 39th Avenue. The Airport Basin tributary be-gins on the Alachua County Fairgrounds, crosses under NE 39th Avenue twice and drains into pine flatwoods which connect with Gum Root Swamp Conservation Area. 7.2.1 Main Channel NE 53rd Avenue to Brittany Estates The main channel of Little Hatchet Creek emerges from a 24-inch RCP culvert un-der NE 53rd Avenue and flows southeast for 1.5 km before entering Brittany Es-tates Mobile Home Park subdivision. Shortly after emerging from beneath NE 53rd Avenue, the main channel is joined by a tributary flowing east from NE 15th Street. Here, Little Hatchet Creek mean-ders slowly southeast, bordered by low, stable banks with wide riparian zones of native vegetation. Streambed erosion is very slight and scouring is low. The creek flows east through Brittany Estates for approximately 0.3 km in the form of a dredged channel and then is joined by Lateral A tributary. The banks of the channel are low and moderately stable and reinforced with retaining walls of concrete and rock. However, natural vegetative riparian zones on either side of the creek are less than 2 m wide. The streambed is moderately eroded with some evident

of bald cypress and black gum, upland scrubby flatwoods, and a 20-acre pasture. Much of this acreage is in public ownership. Ironwood Golf Course is owned by the City of Gainesville, and Gum Root Park and Gum Root Swamp Conservation Areas are cooperatively managed by the City of Gainesville and the St. Johns River Water Management District.


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scouring and sand smothering. Little Hatchet North Branch at Airport From Brittany Estates, Little Hatchet Creek flows east under Waldo Road and through the Airport Industrial park via a

large 72-inch RCP for approximately 0.75 km. This area of Little Hatchet Creek is heavily sand smothered and streambed erosion is moderate with some scouring observed. Banks here are moderately un-stable. Little Hatchet continues for 0.5 km and ends in a 10-foot concrete culvert under an auxiliary runway at Gainesville Regional Airport. Banks here are high, steep and unstable due to severe erosion occurring due to the large volume of rain-fall runoff from the runway. One area near a culvert along this segment is heavily eroded with large amounts of sand deposited in the creek. Streambed erosion is moderate with some areas scoured to shell/rock surfaces. Although this area is enveloped in a wide, forested riparian zone, banks are steep, unstable

and flood damaged. Outer banks observed along the length of this segment extend up to 4-6 meters in height and the creek has an incised inner channel 1-2 meters deep. The streambed is scoured down to a clay substrate in many areas along this section. Little Hatchet Creek western segment south of NE 39th Avenue Little Hatchet Creek emerges south of NE 39th Avenue through a double box culvert. This section of the creek is intermittently dry and during dry periods may have only a few shallow pools of water near the cul-vert. Banks near the culvert are 1.5 meters high and moderately stable with some signs of erosion. Several meters beyond the culvert, the height of the creek banks drop to floodplain level. The creek contin-ues to flow in this manner through the floodplain for about 0.30 km, becoming braided as it flows into a cypress swamp. Little Hatchet Creek eastern segment north and south of NE 39th A little more than 0.5 km north of NE 39th Avenue, Little Hatchet Creek is dominated by intermittent sheet flow with no discern-able channel. Continuing south, an old tram road with a collapsed bridge is ob-served. Beyond the tram road, Little Hatchet Creek becomes a natural flowing stream winding its way between low banks through a heavily vegetated forest. Bank conditions here are stable and low with no evidence of erosion. The streambed itself shows very slight scouring in a few places. The channel flows under NE 39th Avenue via a triple box culvert and continues southeast as a straight channel for approxi-mately 0.12 km. Banks here are steep and moderately unstable. The channel is sev-eral meters wide with moderate bank ero-

Severely eroded bank along Little Hatchet Creek near the airport


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streambed in this location has been scoured to a width of approximately 3 me-ters. NE 23rd Avenue to NE 31st Avenue At NE 23rd Avenue, Little Hatchet Creek emerges from a 24-inch concrete single box culvert and is bordered on both sides by parking lots. The area is exclusively commercial and the creek receives storm water runoff from many parking lots and the roof drains of several businesses. Ero-sion has deepened the creek to a narrow channel that is less than 1 meter across. Flow is low here with some sections con-taining pools of stagnant water. Channel width ranges from 2 to 4 meters. The stream banks show signs of heavy erosion

due to construction and are steep and deeply incised, ranging in height from 1 to 4 meters. No natural vegetative riparian zones are present. Portions of the creek are fenced on either side with less than 0.5 meters between the creek and the fence. A significant amount of asphalt rip-rap is present in the streambed. Some sections of the creek bank have caved in. A strong

sion. Some scouring of the streambed is visible. As the stream continues, its banks flatten, the streambed narrows and be-comes more sinuous, a good indication of recovery to a more natural state. From this point, Little Hatchet Creek flows through a forested cypress wetland for 0.60 km. 7.2.2 Description of the Tributaries: NE 9th Street and NE 19th Place to NE 23rd Avenue Lateral A tributary of Little Hatchet Creek emerges from a 18-inch concrete culvert under NE 9th Street as a uniformly dredged channel. The segment is flanked by How-ard Bishop Middle School and Metcalf Elementary School on the west bank and low density housing on the east bank. The channel banks are steep (2 meters high) and moderately unstable in several places. From NE 9th Street to NE 17th Terrace there is no natural vegetative riparian zone on either side of the channel other than a few feet of grass and trees. The streambed is approximately 2 meters wide and devoid of aquatic vegetation but contains some grasses and weeds. Streambed erosion is slight and sand smothering is low in most areas of the channel with the exception of areas near storm drains, which are sand smothered to a depth of a 0.5 meters. The creek receives runoff from several school parking lots and access roads, playing fields, retention ponds and residential ar-eas. The residential areas in this portion of the watershed have 18 and 24-inch culverts placed along the west bank. The channel bends sharply 90o to the north at NE 17th Terrace and the deeply incised channel continues for 0.5 km to NE 23rd Avenue, bordered by homes < 1 meter from either bank. This unnatural bend has caused fur-ther erosion and bank instability. The

Little Hatchet Creek near Waldo Road.


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odor of petroleum was evident, probably related to the large number of automotive businesses located in close proximity to the creek in this area. Bank failure due to eroding concrete reinforcement was ob-served at a 16-inch culvert beneath NE 19th Drive. NE 31st Avenue to 0.40 km north of NE 39th Avenue This stretch of Little Hatchet emerges from a double box culvert at NE 31st Ave-nue as a dredged canal. In this area, the creek is bordered on both sides by a ma-ture pine plantation. The banks are high, steep and moderately unstable. The streambed is 3 to 4 meters wide, scoured in some areas and sand smothered in oth-ers. The creek flows under SR222 through a double box culvert and contin-ues north for 0.5 km past a U-Haul Facil-ity and Double Envelope Corporation. The creek along this section is approxi-mately 4 meters wide with bank heights of 2 to 3 meters. Bank erosion is severe, with some caving. Streambed erosion is moderate with scouring and rerouting of the channel noted in several areas. The channel continues to flow northeast past a large retention pond and wooded area. It joins the main channel near Brittany Es-tates subdivision. Ironwood Tributary This tributary of Little Hatchet Creek be-gins in a small pond on the northwestern side of Ironwood Golf Course and flows east for approximately 1.2 km to meet the southern branch of Little Hatchet Creek, just west of Waldo Road and north of NE 39th Avenue. For the first kilometer of its length, Ironwood tributary is a channel-ized. Through this section, the riparian

zone of the creek ranges from 0 to 5 meters and consists of a mixture of golf course grass and native forested habitat. Erosion is slight and the creek banks are mostly stable with an average height of 1.5 me-ters. Streambed scouring and sand smoth-ering is low. Several 24-inch corrugated metal pipe culverts direct runoff into the creek from the golf course. The creek then flows for 0.35 km through a mixed pine/oak forest bordered to the north by a wide, well-maintained fire road. Increased ero-sion due to fire is evident, in some areas the deeply incised and scoured banks are surrounded by open, scorched forest. The streambed is scoured to clay substrate in these areas. Airport Basin Tributary The Airport Basin tributary is a small creek in the lower portion of the Little Hatchet Creek watershed that begins in a wooded area on the Alachua County Fair-grounds. It runs approximately 0.16 km southeast through grassy open fields before crossing under NE 39th Avenue. Banks are

Little Hatchet Creek wetland near SR26.


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7.3 Physical Habitat and Biology Some segments of Little Hatchet Creek have potential habitat to support diverse and healthy populations of macroinverti-brates and other aquatic species. Other sections of the creek lack sinuosity due to channelization, and are located in dense populated residential, business, or institu-tional areas. Much of the natural flow of Little Hatchet Creek has been altered due to changes in land use in the watershed. Over the past century, considerable com-mercial, residential and industrial develop-ment occurred in the area that has elimi-nated many areas with natural buffer zones along the creek. Two Rapid BioRecons were completed

between 1997 and 2001. In 1997, FDEP personnel from the Jacksonville Northeast District conducted a BioRecon at Little Hatchet Creek at SR 26 (FDEP 1999), which rated the creek as suspect. During 2001, the same site received at rating of impaired when ACEPD and WAV per-sonnel conducted a second BioRecon on Little Hatchet Creek. BioRecon results are presented in Table 7.1. In both assess-ments, Little Hatchet Creek scored a 0 on the EPT index, well below the value of 10, the lowest value indicative of clean waters. The collection of water quality samples and macroinvertebrates for the BioRecons on Little Hatchet Creek was somewhat difficult because the creek is intermittently dry and many areas of the creek are braided or in the form of sheet flow through swamps.

Lateral A and Airport area Examples of areas containing poor habitat for macroinvertebrate populations include much of the areas along Lateral A tribu-tary from NE 9th Street to NE 31st Avenue and parts of Airport Basin Tributary. These are poor areas for macroinverte-brate populations due to heavy erosion, increased water velocity during storm events, and a lack of natural vegetative

Helichus sp.-A species found in Little Hatchet Creek

low and stable and have no indication of streambed erosion. From NE 39th Avenue, the channel emerges from a 48-inch con-crete culvert and runs south, bordered for about 0.5 kilometer by pine flatwoods on the east bank. The west bank of the chan-nel is flanked by a retention pond. The creek then turns east and continues flowing past the Correctional Facility before it crosses under NE 39th Avenue via a con-crete culvert. Emerging from this culvert, the creek flows through a narrow, dredged channel, with low stable banks and a slightly scoured streambed. The creek continues in this dredged channel for sev-eral meters before becoming increasingly sinuous and then braided as it flows east for about 1 kilometer through a pristine pine swamp. This swamp shows evidence of being a sheetflow area during rain events and is likely another source for Lit-tle Hatchet baseflow. Airport basin tribu-tary may not be hydrologically connected to the main channel of Little Hatchet Creek except during periods of high flow.


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riparian zones. Along Lateral A tributary, pollution runoff from area industries that have unused vehicles and discarded appli-ances may contribute to an unfavorable environment for macroinvertebrates. Ap-proximately 44% of the areas adjacent to the creek have been altered, especially the sections along Lateral A and the northern part of the creek that flows through the Airport Industrial Park and the airport. Such activity has lead to increased flow and erosion during and immediately fol-lowing storm events. This has lead to the accumulation of sediments on potential productive macroinvertebrate habitats, such as aquatic plants, root mats and snags. These sediments smother the substrates and prevent them from serving as habitat for macroinvertebrates and other animal species. Suspension of sediments in creeks also reduces the growth potential of certain plant species and interferes with oxygen levels for fish and other aquatic fauna. Much of the creek bed in the disturbed ar-eas of the watershed exhibit heavy sand smothering and provides habitat for few species of macroinvertebrates. Main Channel near NE 53rd Avenue The main channel of Little Hatchet Creek emerging from under NE 53rd Avenue is a good example of a recovering natural creek supporting various species of macro-invertebrate populations. Here, Little Hatchet flows slowly southeast bordered by low, stable banks with some wide ripar-ian zones composed of native oak, pond cypress (Taxodium ascendens), and maple with a diverse understory of wax myrtle (Myrica cerifera), Lyonia spp., and cherry (Prunus spp.). Aquatic macrophytes here include lizard tail (Saururus cernuus), Ludwigia spp., and spiderwort

(Tradescantia spp.). Streambed erosion is very slight and scouring is low. Substrate diversity here is high with riffles and pools followed by lengthy segments of exposed, sediment-free root systems, de-bris jams, and leaf packs shown to support some macroinvertebrate taxa including Diptera and Decapoda. Although sub-strate diversity is high, substrate availabil-ity is suboptimal here and habitat smoth-ering occurs (Line 2002).

Eastern and southern region Over 56% of Little Hatchet Creek, such as its eastern and southern portions, flows through rural areas with natural habitats including forest and forested wetlands. Much of this land is state owned and sev-eral areas within these habitats have healthy ecosystems with potential habitat for macroinvertebrates and other aquatic species. The major limiting factor that reduces the potential of these areas to sup-port large macroinvertebrate populations is the fact that the creek is intermittently dry, especially in areas where the land is swampy, banks are low and the channel is braided. The eastern portions of Airport Basin tributary and the eastern areas of the main channel of Little Hatchet Creek, near sampling stations LHAT 26 and LHAT26E, contain areas of potential macroinvertebrate habitat. During the wet season, these areas are comprised of pine flatwoods with pond cypress domes that have the potential to house various macro-invertebrate species. The areas have low stable banks, sinuous flow patterns, un-dercut banks, exposed roots and many in-stream snags. This sheetflow area drains to Gum Root Swamp Conservation Area. Floodplain areas such as this serve as im-portant water storage areas and also func-


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phorus in Little Hatchet Creek. Several potential point sources regulated by the Alachua County Hazardous Materi-als Management Code are located in the Airport Industrial Park near Gainesville Regional Airport. These include Clariant Inc., Fabco-Air Inc., and Vital Industries. Clariant Inc., formerly PCR Inc., manu-factures specialty organic chemicals.

7.4 Pollution Sources Point Sources Much of Little Hatchet Creek flows through rural areas of Gainesville where few point sources of pollution exist. However, some facilities in the watershed may serve as point sources of pollution. The first point source along the main channel of Little Hatchet Creek is the wastewater treatment plant for Brittany Estates Mobile Home Park. Brittany Es-tates has over 300 mobile home sites and its wastewater treatment facility has a ca-pacity of 0.06 MGD of annual average daily flow. The facility consists of pump-ing stations, aeration basins, secondary clarifiers, hypochlorination disinfectants and dechlorination systems. Final effluent is discharged into a 0.6 acre polishing pond before flowing into Little Hatchet Creek. The FDEP performed a biological assessment of the creek downstream of the wastewater discharge (Fifth Year Study) but results are not yet available. The discharge contains elevated levels of nitrogen and phosphorus. Although Flor-ida currently does not have maximum dis-charge limits for phosphorus and nitrogen in Class III surface waters, levels of these nutrients in the treated effluent from Brit-tany Estates is often elevated. Occasion-ally, nutrient levels are as much as one order of magnitude above those normally found in Little Hatchet Creek. Total phosphorus in Brittany Estates effluent from 1999 through March 2002 ranged from 0.15 mg/L to 4.04 mg/L with a me-dian value of 2.08 mg/L. Nitrate + nitrite values during the same time period ranged from 0.035 mg/L to 11.8 mg/L with a me-dian of 0.64 mg/L. Figure 7.3 compares the values in the treated effluent with background values of nitrogen and phos-

Table 7.3 Comparison of nutrients in Brittany Estates effluent with other sites on Little Hatchet Creek.

0

0.5

1

1.5

2

2.5

Nutrie

nts (m

g/L)

LHTNB LHAT26 L H T 2 6 E Br i t tanyE s t a t e sEff luent

T P NO2+NO3

There have been numerous and repeated chemical releases at this facility in the re-cent past, and contamination of the surfi-cial aquifer at the site was detected in

Aerial photograph of the Clariant Facility


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1984. Contamination of the surficial aqui-fer is widespread, covering much of the eastern part of the facility. A groundwater remedial action plan for groundwater cleanup began in 1999 (Bird 2000). Fabco-Air Inc., manufactures pneumatic control devices, and formerly used an or-ganic solvent as a cleaner, which generated a waste of residual solvents and chromium. From 1978 to 1986, a drainfield system was used for disposal of these wastes. In 1988 the FDER (now FDEP) checked for soil and groundwater contamination at this site and determined that both were con-taminated. However, Little Hatchet Creek did not appear to be affected and the Murphree well field is located upgradient of the site (AT&E 1988). The impacted soil was removed in 1987 and the ground-water contamination has been placed under “monitoring only “ (MO) status. Fabco-Air currently uses a water-based cleaner and its waste is discharged to the munici-pal sanitary sewer system (AT&E 1988). Vital Industries produced television broad-cast switching equipment from 1973 until the late 1980s. Organic solvents and de-greasers were used in the production proc-ess. Wastes were stored in 55 gallon drums on site, and in 1984, an inspection by FDER and ACDES (now FDEP and ACEPD) determined that small amounts of organic compounds such as tetrachloro-ethylene (TCE) had contaminated ground-water in the area. However, a follow-up contamination assessment found no evi-dence of migration of the contamination beyond the property boundary (ECT 1990). Other point sources in the vicinity of Gainesville Regional Airport include a landfill, a shooting range and an old burn

site. The airport landfill (now closed) is located north of Little Hatchet Creek and consists of three areas: a yard trash area, a garbage area and a construction and demolition debris area. (ESE 1985). A 1986 Groundwater Investigation Report (GIR) conducted by the FDEP found that the water table aquifer had been contami-nated with lead, chromium, benzene, and TCE (FDEP 1986). Possible sources of these contaminants (in addition to the landfill) are the shooting range and old burn site located adjacent to the landfill. The shooting range was opened in 1972 and is currently used by the public as well as area law enforcement agencies (ESE 1985). Bullets used by Law Enforcement officials at this site from 1972 to 1985 were made up of 90% lead, 6% tin, and 4% antimony. 1978, a lead recovery pro-ject was completed at the firing range. A private firm sifted the berm surrounding the range and removed several tons of lead from the site. However, the berm was severely damaged in the process. Lead contamination may pose serious en-vironmental and human health risks. The old burn site is located on the north side of the main airport runway, south of Little Hatchet Creek. This site was operated from the late 1970’s until approximately mid 1981 by the City of Gainesville Fire Department, which practiced extinguish-ing fires in simulation of an airplane crash (ESE 1985). Aviation fuel was normally burned in the fires, but at times, waste or-ganic chemicals from PCR Inc (presently Clariant, Inc.) were used to fuel these training fires. Records of the site indicate that 1,500 gallons of flammables were used at each burn. The organic wastes burned were intermediate compounds in the manufacture of silicone oils and rub-


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7.5 Water Chemistry ACEPD personnel have been sampling three sites on Little Hatchet Creek since February 1998: North Branch of Little Hatchet Creek at the Airport (LHTNB), Little Hatchet Creek at SR 26-western split (LHAT26), and Little Hatchet Creek at SR 26-eastern split (LHT26E). These sites are in the eastern portion of the watershed and may not be representative of the urban, channelized portions of the creek such as Lateral A tributary. Field Parameters Parameters measured in the field include water temperature, pH, specific conductance and turbidity. Results for three sites on Little Hatchet Creek are shown in Table 7.2. Median water temperatures for Little Hatchet Creek at these sites were comparable to other low

bers and included hexamethyldisilazane, hexane and hexamethyldisiloxane (ESE 1987). Between 1986 and 1992, 610 tons of contaminated soil were removed from the area and there has since been a signifi-cant reduction in the amounts of the con-taminants in the groundwater at the site (ESE 1992). Nonpoint Sources Potential nonpoint pollution sources in the Little Hatchet Creek watershed may be in the form of golf course runoff and petro-leum product discharge from the large number of automotive businesses located in close proximity to the creek. Golf course runoff is a potential source of pol-lution to the Ironwood tributary of Little Hatchet Creek that flows through Iron-wood Golf Course. The creek is main-tained as a drainage canal by Ironwood staff and approximately half of its 1.2 km length is devoid of any natural vegetative riparian buffer zone. Instead, the golf green is mowed to the edge of the creek. Such grassy monocultures that eliminate riparian buffer zones can enhance pollut-ant runoff to creeks. Additionally, over-use fertilizers and herbicides required to maintain such monocultures can also de-grade surface water quality. Petroleum product discharge is a possible source of nonpoint pollution along the south branch of Little Hatchet Creek from NE 31st Ave-nue to NE 27th Avenue, west of Waldo Road. In this area, several automotive businesses, repair and storage shops, a pool service, ironworks, and a furniture refinishing company are located in close proximity to the creek. Increased poten-tial for the contamination of surface water exists in this area due to the fact that no natural vegetative riparian zones exist be-

tween the businesses and the creek. Any chemicals spilled on the impermeable sur-faces surrounding these businesses are washed directly into the creek.

LHTNB LHAT26 LHAT26E

Water Temp (ºC)

20.2 18.6 20.9

pH (SU) 7.3 6.2 6.6

Sp. Cond. (uS/cm)

228 116 144

Turbidity (NTU)

3.8 2.4 1.8

DO (mg/L)

8.1 3.8 5.8

Table 7.2 Field Parameters for three sites on Little Hatchet Creek


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than other comparable creeks and other sections of Little Hatchet Creek. A possible source for these high phosphorus values is proximity to Hawthorn Group outcrops. The creek in this area likely receives baseflow that has come into contact with the Hawthorn Group sediments, sands, clays, carbonates and phosphates. The phosphates in these sediments may naturally elevate the phosphorus concentrations of the water at this location. Nitrogen values in Little Hatchet Creek are also comparable to those found in other area creeks. However, median nitrate + nitrite values for LHTNB are much higher than the other two sites, evidence of the effect of urban runoff on the creek in this area (Figure 7.4). LHTNB receives runoff from the airport and the airport industrial park, which likely contains petroleum and fertilizer residues. Coliform Bacteria Only one site on Little Hatchet Creek (LHTNB) showed fecal coliform levels higher than the one time allowable limit of

end median temperatures for similar creeks in the Gainesville area, including Lake Forest Creek at CR329B (LFC329B, 20.2oC) and Possum Creek at NW 16th Avenue (POSNW16, 21.8 oC). The median pH values are consistent with similar streams in the area, especially the low pH value of 6.2 standard units at LHAT26, which is comparable to the pH of Hatchet Creek at SR 26 (HAT26) at 5.8 SU. Both these creeks flow through forested wetlands at these locations. Water flowing through forested wetlands is tannic and naturally low in pH. Specific conductance in Little Hatchet Creek is comparable to other median specific conductance values in the area, such as LFC329B (180 uS/cm) and POSNW16 (239uS/cm). Turbidity in Little Hatchet Creek is also comparable to other Gainesville area streams. Median dissolved oxygen (DO) values in Little Hatchet Creek are comparable to those found in other creeks with good flow and natural vegetative riparian zones. The low DO at LHAT26 could be related to the creek’s intermittent nature and the low flow in the forested wetland located upstream of this sampling location. DO values in wetlands are typically around 3 mg/L, likely a result of low flow and relatively high concentrations of organic carbon in the water.

Nutrients The values of all forms of baseflow median phosphorus in Little Hatchet Creek are higher than those found in the other creeks in the area. Figure 7.3 compares total phosphorus data in Little Hatchet Creek with other similar creeks. The North Branch of Little Hatchet Creek (LHTNB) is much higher in phosphorus

0

0 .05

0.1

0 .15

0.2

0 .25

0.3

0 .35

Total

Phos

phor

us (m

g/L)

LHTNB LHAT26 LHT26E L F C 3 2 9 B HAT26

Figure 7.3 Comparison of Median Total Phosphate Values for Gainesville Creeks


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800 fecal coliform colonies /100mL (FDEP 1996). Samples were collected from March 2001 to the present and on two occasions, LHATNB had values of 1,700 and 900 CFUs/100 mL respectively. Potential sources of fecal coliform bacteria include runoff from animal (wild and pet) and human activity, malfunctioning septic systems, and failing sewer lines or private connections to these lines.

7.6 Stormwater Storm events were monitored on Little Hatchet Creek by ACEPD personnel in 2000 and 2001. During the dry season, flow in Little Hatchet Creek is intermittent and many sections of the creek are often dry. Additionally, much of the eastern portion of the creek travels via sheet flow through swamps where flow is typically low. This low flow allows pollutants and debris to settle out of the water column and into the sediments on the creek bed. Storm events can cause the volume and velocity of water flow in Little Hatchet Creek to

increase dramatically. In addition to mo-bilizing settled sediments and their associ-ated debris and pollutants, this increased stormwater flow from streets and lawns washes large amounts of pollutants into the creek. Figures 7.5, 7.6 and 7.7 illus-trate the large spikes in the values of nu-trients and suspended solids in Little Hatchet Creek during storm events.

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Nitra

te + N

itrite

(mg/

L)

L H T N B L H A T 2 6 L H T 2 6 E L F C 3 2 9 B H A T 2 6

Figure 7.4 Comparison of NO2 + NO3 Values for Gainesville Area Creeks

0.0

0.2

0.4

0.60.8

1.0

1.2

1.4

Tota

l Pho

spho

rus

(mg/

L)

Little H a t c h e t C r e e k N o r t hBranch a t A i rpor t

Base f low S t o r m

Figure 7.5 Total Phosphorus Baseflow and Stormflow data for LHTNB.

Stormflow on Little Hatchet Creek


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7.7 Ecosystem Health Biological Integrity Many areas in Little Hatchet Creek have diverse habitats that support a wide array of avian, reptilian, and mammalian spe-cies. Parts of the Little Hatchet Creek wa-tershed are also a refuge for rare migrant species such as the black-headed gull, spotted at the north end of Newnans Lake in May 2000 (Rare Bird Alert, Cape Cod Connection 2000). Property surrounding Little Hatchet Creek on the Ironwood Golf Course on NE 39th

Avenue totaling 477 acres is one of six tracts of land in Alachua County slated for preservation. It has been awarded 1.17 million dollars from the Florida Communi-ties Trust. The land is being considered for purchase under the Alachua County Forever Land Conservation Program (Vardeman 2002). Gumroot Swamp Park and Conservation Area provide a remark-able model of contiguous and diverse pro-ductive native habitats capable of support-ing a range of macroinvertebrate and verte-brate populations. Distinct among other areas in the watershed, Gumroot Swamp areas range from floodplain swamp of bald cypress (Taxodium distichum) and black-gum trees to upland scrubby pine flat-woods and pond cypress domes to mesic hardwoods and pastures. Dominant can-opy species include oak, maple, sweetgum, cypress, and pine. Understory species in-clude cherry, southern elderberry, wax myrtle, palmettos and exotics Ligustrum spp. and camphor (Cinnamomum spp.). Aquatic macrophytes include native juncus (Juncus spp.) and St. John’s Wort (Hypericum spp.), exotic species such as taro and parrot feather (Myrofilum spp.), native weeds including crane’s bill

Gumroot Swamp Conservation Area

0.00.10.10.20.20.30.30.40.40.5

Tota

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ate

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trite

(m

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Little H a t c h e t C r e e k NorthBranch a t A i rpor t

Bas e f low S t o r m

Figure 7.6 Nitrate an Nitrite Basseflow and Stormflow data for LHTNB.

0.010.020.030.040.050.060.070.080.0

Tota

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Solid

s (m

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Little H a t c h e t C r e e kNor th Branch a t A i rpor t

Bas e flow S t o r m

Figure 7.7 Total Suspended Solids baseflow and stormflow data for LHTNB.


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(Geranium carolinianum) and lizard tail, and exotic weeds including alligator weed (Alternanthera philoxeroides) and baby tears. Contiguous wetland habitats support the development of many species, sustain water dependent species such as fish and wading birds, and serve regularly as wild-life corridors for many vertebrate species from alligators to foxes. Physical Integrity The main channel of Little Hatchet Creek has many areas of natural sinuosity and a large portion of the creek flows as sheet flow through swamps. However, one problem area is the section of creek that flows through Gainesville Regional Air-port. The creek has been channelized through this area through large concrete culverts approximately 3 meters wide. Runoff from runways has caused serious problems and many culverts have areas of significant sand deposition. Erosion prob-lems in the creek due to runoff are evident even in relatively pristine areas of the creek. After the creek exits the airport, it flows through a wooded area with a wide, forested riparian zone. However, the creek bed in this area is steep, deeply cut, steep unstable and flood damaged. Inner banks along this segment are 1-2 meters high and the outer banks are 6-7 meters in height. The creek channel then becomes braided and eventually flows as sheet flow as it enters Gum Root Swamp Conservation Area.

Much of Lateral A tributary has been dredged and channelized. There are very few natural vegetative riparian zones in this area, and surface water runoff flows directly into the creek. At the southern end of Lateral A, the channel makes a sharp 90

7.8 Summary and Recommendations Existing Conditions The upper reaches of the Little Hatchet Creek watershed is highly urbanized. Much of the headwaters have been chan-nelized to facilitate drainage and reduce flooding potential. During rain events, high volumes of water flow into the ditches and storm drains that lead to the creek. In residential and industrialized areas in the vicinity of the airport, little infiltration takes place. Much of this ur-ban development occurred prior to state and local requirements for stormwater management. The lack of retention ponds in this area allows direct discharge of non-treated stormwater to enter Little Hatchet Creek. Rainfall cannot slowly infiltrate and enter the creek through surficial aqui-fer spring and seeps, but instead flows rapidly into the creek as the rainfall event

degree turn north. This unnatural bend has caused lateral erosion and bank failure in several places and widened the creek bed to around 8-10 feet. Many sections of Lateral A have fences in close proximity to the creek. A significant amount of as-phalt is mixed into the streambed in the section between NE 27th Avenue and NE 31st Avenue. A concrete culvert at NE 19th Drive is eroding and caving into the creek. Bank heights along this segment can reach up to 6 meters.

Ironwood tributary is maintained by Iron-wood Golf Course and parts of the banks are mowed right to the edge of the creek. However, many portions of the creek flowing through the golf course are sur-rounded by natural vegetation. These sec-tions of the creek show little erosion and banks are stable at a height of 1.5 meters.


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occurs. This process allows runoff to di-rectly enter the creek (1) transporting ex-ternally generated sediments directly into the creek, (2) causing in-stream erosion and bank failure, and (3) transporting pol-lutants, such as petroleum products, di-rectly into the creek. In many of the ur-banized and channelized sections of Little Hatchet Creek, no natural buffers protect the creek. This intensifies the erosion and pollutant transport to the creek.

Some areas in the upper watershed have been ditched and drained to reduce flood-ing, but retain some natural vegetation in the form of forested wetlands including cypress domes. These areas are important because, although ditched and drained, they contain relatively little impervious area. The areas in the lower watershed in and around Gum Root Swamp are impor-tant in reducing the impacts of urbaniza-tion on Newnans Lake. These forested swamps allow sheet flow, which reduces water velocities and turbidity. Reduced velocities also allow nutrient uptake to occur, potentially reducing the levels of anthropogenic nitrogen and phosphorus that enter Newnans Lake.

Treatment and Restoration The goal of treatment and restoration ac-tivities in the Little Hatch Creek water-shed include (1) retaining existing natural forested lands, (2) providing increased stormwater treatment and (3) increasing the native riparian buffer in the urbanized areas of the watershed. Increasing the widths of riparian buffers which are planted with native vegetation, and pro-viding stormwater treatment are key resto-ration activities that will aid in improving the in-stream biological habitat, decreas-

ing bank and streambed erosion and sedi-mentation, and enhancing water quality. An important short-term goal is to increase public awareness of the importance of res-toration. Educating the residents as well as owners and personnel employed in indus-trial and commercial activities in the wa-tershed, is an important step in reducing nonpoint source pollution from residential activities and businesses.

Many treatment and restoration activities require large capital investments, complex engineering designs, and extensive land area. One of the greatest problems in the basin is management of stormwater vol-ume and velocity in the urbanized areas of the watershed following rainfall events. Lowering these velocities will result in less sediment movement through the system in the form of in-stream bank erosion and sediment deposition, and will improve wa-ter quality. Major restoration activities requiring significant capital expenditures include:

• Property acquisition in the headwaters

of the watershed to retain existing natural areas

• Property acquisition and revegetation

to increase natural buffer widths along the stream corridor

• Addition of stormwater basins through-

out the watershed for water treatment and storage to attenuate the volume and rate at which stormwater enters the creek

• Retrofit of existing stormwater systems

in the industrial and commercial areas south and west of the airport, airport


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industrial park, and the airport itself to store and treat stormwater before dis-charge to the creek

• Continue monitoring activities at the

former Airport Landfill and monitor-ing and groundwater remediation at other commercial and industrial facili-ties to assure that contaminants do not adversely impact the creek.

It is critical to increase buffer widths and improve the quality of the existing buff-ers. Areas of concern that have little buff-ers include the following: (1) residential areas south of NE 39th Avenue and west of Waldo Road, (2) the industrial and commercial areas between NE 23rd Ave-nue and NE 53rd Avenue in the vicinity of Waldo Road, (3) Brittany Estates Mobile Home Park, (4) Ironwood Golf Course, (5) the Airport Industrial Park, and (6) Gainesville Regional Airport. Increased storage of stormwater to attenuate rate and volume is also needed in these same areas. Unlike many of the more urbanized water-sheds, the Little Hatchet Creek watershed still contains many undeveloped parcels, areas that could be developed for storm-water treatment. Public education pro-grams are important and should be in-cluded in short term goals to this water-shed. Educational activities can be tar-geted to specific commercial, industrial, and residential activities or neighbor-hoods.

chapter 7: little hatchet creek 7.1 introduction the little hatchet

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