In this section
2014 Water quality status and trends report
- Summary table
- Summary table
- Surface water
- Summary tables
ORD (Ocklawaha River)
Location: latitude: 29°12’ 55.665”, longitude: 81°59’ 09.778”, GPS datum—WGS-1984 Station ORD is located on the Ocklawaha River downstream of State Road 40.
Point sources: Rolling Greens Mobile Home Park and the Silver Springs Regional wastewater treatment facility are located within a five-mile radius and within the drainage basin of this water quality site.
This site is located on the Ocklawaha River just downstream of the State Road 40 Bridge in Marion County in north-central Florida. It is approximately 8 miles east of Ocala, Fla., and can be reached easily using the public boat ramp nearby.
The waters of the Ocklawaha are dark tannic waters that flow down from the Harris Chain of Lakes in Lake County. This area is very popular with fishermen, boaters, and outhoor enthusiasts from throughout the state. The Silver River and its clear waters can be reached by going upstream less than a mile and this area is great for kayaking and canoeing. Abundant wildlife, even a colony of monkeys, can be found along the banks. The shorelines offer magnificent stands of cypress trees and wetland vegetation. The Ocala National Forest surrounds the Ocklawaha River and prevents overdevelopment of this great resource.
All of the maps and charts shown below were created using a customized GIS data summary tool, with the watershed generated by Arc Hydro for this monitoring station. More information about Arc Hydro can be found by going to the Technical background page. From that page, a description of the customized GIS data summary tool can be accessed.
Spatial data summaries
2000 population density
Population data is collected by the Census Bureau every 10 years and is used to show the distribution of population in a number of ways. Population density has a direct impact on land use, which effects water quality in areas around or near water bodies. This map displays the 2000 population density per square kilometer within this surface water catchment. The legend shows the area for each class in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for the 2000 population density.
General land use 2000
Land use, which is usually derived from aerial photography by photo interpreters, shows the distribution of land and how it is used. Land use affects the water quality of water bodies through water runoff within a surface water catchment. This map displays the distribution of eight categories of general land use within this surface water catchment. The legend shows the area for each category in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for general land use 2000.
The geology of the state of Florida was delineated by the Florida Geological Survey. Water quality is impacted by the underlying geology of streams and lakes. This map displays the underlying geological formations within this surface water catchment. The legend shows the area for each type of formation in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for geology.
Physiography describes the earth’s exterior physical features. These are divided into general groups and then subgroups containing features such as uplands, hills, ridges, plains, valleys, karst, etc. Water quality is affected through water runoff by physiography. This map displays the more detailed physiographic subdistricts within this surface water catchment. The legend shows the area for each subdistrict in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for physiographic divisions.
Rainfall data comes from radar imaging as well as rainfall gauge surveys. Rainfall affects water quality through runoff within the surface water drainage basins. This map displays the total daily rainfall in inches for each pixel for 2004 within each surface water catchment. The legend shows the area for each rainfall range in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for 2004 rainfall.
St. Johns River Water Management District and other public lands
The St. Johns River Water Management District (SJRWMD) purchases lands that are in environmentally sensitive areas to protect the water resources on, beneath or adjoining the property. Water quality is affected in water bodies adjacent to these protected lands. This map displays the lands owned, jointly owned, being considered for purchase, or lands through which SJRWMD has an easement. The legend shows the area of these lands in acres and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for SJRWMD and public lands.
Soils drainage characteristics can also impact surface water runoff, a source of nonpoint pollution for adjacent water bodies, which effects water quality. This map displays water bodies and soil drainage characteristics. The legend shows the area of these soils in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for soils drainage.
5-foot elevation — DEM
Land elevation influences rainfall runoff, which effects the surface water quality, as water moves through the landscape to the rivers, streams, and lakes. This map with accompanying legend displays the maximum (MAX), minimum (MIN), range, standard deviation (STD) and mean of 5-foot elevations within the surface water drainage area (watershed). More complete metadata can be found by clicking on the metadata link for 5-foot elevation-DEM (Digital Elevation Model).
In some areas of SJRWMD, the Floridan aquifer is at or near land surface and is vulnerable to pollutants that threaten our drinking water supply. It is especially important to preserve surface water quality in these areas. This map displays recharge to the Floridan aquifer in inches per year (in/yr) within this surface water drainage catchment. Discharge, where the potentiometric surface is greater than the land surface elevation, is also shown. The area for each class is shown in square kilometers and the percentage of area in descending order. More complete metadata can be found by clicking on the metadata link for recharge 1995.
Arc Hydro model
The map below contains selected features from the St. Johns River Water Management District (SJRWMD) Arc Hydro geodatabase. The introduction of the SJRWMD Arc Hydro geodatabase made the creation of these fact pages possible, by providing improved geographic information system (GIS) data that has been combined into a GIS network. This hydrologically based network does for water resources what the commonly used mapping websites (such as MapBlast, MapQuest and GoogleMaps) have done for travel planning, except that instead of interstates, highways and roads, this hydrologic network shows streams, rivers, lakes and wetlands. Similar to transportation mapping sites, information about water resources has been related, or linked, to the GIS network and can be easily accessed. The legend to the right of the map includes the Arc Hydro network, Arc Hydro Polygon Feature Classes and HydroPoints. The features included in the Arc Hydro Network exist to establish relationships based on surface water flow. The lines (HydroEdges) may represent streams or rivers, which are commonly displayed as lines on maps. The lines may also represent, in a “shorthand” way, the concept of surface water flow through a lake or a wetland, which are not routinely displayed as lines. The features in the Arc Hydro Polygon Feature Classes and HydroPoints represent some of the water resources information that has been linked to the Arc Hydro GIS network. HDS in the map legend below refers to the district’s Water Resource Information program and NWIS refers to the National Water Information System, which is part of the United States Geological Survey (USGS). See Technical Background for a more detailed explanation of the SJRWMD Arc Hydro technology and its features.
Clicking on the Methodology link will direct you to information about how water quality samples were collected, analyzed, and summarized for this fact page. View the most recent Water Quality Status and Trends Report.
The Ocklawaha River is sampled every other month, at State Road 40 in central Marion County, as part of the ambient monitoring program. The river is about 3 meters deep at the sample site and has a narrow temperature range. Major ion concentrations are high enough to result in hard water. The median dissolved oxygen concentration is less than that typically found in district streams. The water has good buffering capacity and a neutral pH. When compared to other stream sites in the district, total organic carbon concentrations and color are less than typically found and result in a high Secchi depth. Total suspended solids, total nitrogen, chlorophyll, and coliform counts were typical of streams, although turbidity and total phosphorus concentrations were lower. The river has good water quality at the sampling site, according to the water quality index.
|Analytes||Data Yrs||N Data||Min||Q1||Median||Q3||Max||Range|
|Water temperature (°C)||15||95||15.60||21.76||22.80||23.90||27.00||mid|
|Secchi disc transparency (meters)||15||90||0.10||1.50||2.40||3.00||22.00||high|
|Color (platinum-cobalt units)||15||92||10.00||10.00||27.50||70.00||250.00||low|
|Specific conductance (µhmhos/cm @ 25° C)||15||96||299.00||420.00||434.00||446.00||467.00||mid|
|Sample collection depth (meters)||15||96||0.50||0.50||0.50||0.50||1.80||high|
|Dissolved oxygen analysis by probe (mg/L)||15||94||1.29||3.75||4.14||4.98||8.03||mid-lo|
|pH (standard units)||15||95||6.51||7.20||7.41||7.52||7.89||mid-hi|
|Total alkalinity (mg/L as CaCO3)||15||89||105.84||144.95||155.37||161.46||174.22||high|
|Total nonfiltrable residue (mg/L)||15||96||-0.50||2.00||4.75||5.00||17.50||mid-lo|
|Total nitrogen (mg/L as N)||15||93||0.83||1.27||1.35||1.54||2.39||mid|
|Total phosphorus (mg/L as P)||15||96||0.03||0.04||0.05||0.06||1.05||low|
|Total organic carbon (mg/L as C)||15||97||-0.66||2.60||4.90||9.46||22.09||low|
|Total calcium (mg/L as Ca)||15||97||30.00||63.60||68.00||70.80||96.21||high|
|Total magnesium (mg/L as Mg)||15||97||5.44||9.51||9.86||10.20||12.40||mid|
|Total sodium (mg/L as Na)||15||97||4.41||6.51||7.00||7.57||14.50||low|
|Total potassium (mg/L as K)||15||97||-2.14||0.90||1.09||1.35||12.20||low|
|Total chloride (mg/L)||15||96||1.00||10.67||11.10||12.07||36.00||low|
|Total sulfate (mg/L as SO4)||15||94||19.14||41.72||44.07||47.24||63.00||mid-hi|
|fecal coliform (MF M-FC broth 44.5° C)||2||8||32.00||36.50||68.50||100.00||330.00||mid|
|Trichromatic uncorrected chlorophyll-a (µg/L)||15||92||-0.34||1.82||2.90||5.22||127.00||mid-lo|
|Hardness (mg/L Ca+Mg)||15||97||138.00||195.00||210.00||218.00||275.98||mid-hi|
|Total filtrable residue (mg/L dried at 180° C)||15||96||128.00||249.00||264.50||274.00||299.00||mid|
|Lab turbidity (NTU)||15||97||0.10||0.80||1.10||1.80||18.20||low|
|Sample site depth (meters)||15||96||1.38||2.50||3.05||3.45||4.20||high|