Piney Z Lake

Hilary B.

Piney Z- A Narrative

General Information:
Lake Piney Z is located in the middle of a chain of lakes called collectively Lake Lafayette . Lake Piney Z is in the eastern part of Tallahassee, Florida. It is directly below a new housing subdivision also called Piney Z. The lake is 193 acres. In the lake there are a number of dikes or fingers. These were built from the muck scraped from the bottom of the lake and they will serve as fishing dikes in the future.

Lake Piney Z has been heavily impacted by man in the past and continues to be impacted with the newly built Piney Z subdivision. It will also continue to be affected by man in the future with the emergence of new subdivisions. In order to understand the effect of man on Piney Z lake, one must first understand the concepts of eutrophication,
Karst topography, and the Floridan Aquifer. Eutrophication is when the plants in a water system die, then decay and settle at the bottom of the lake. Either the decayed materials going down a sinkhole or being washed away by the moving water naturally clean this accumulation at the bottom of the lake. Eutrophication can continue to accumulate if there is no moving water. It can be accelerated by outside nutrient runoff such as fertilizer, sewage discharge, and leaking septic systems. Eutrophication has been a big problem for Lake Piney Z. This is mostly due to the chemical runoff from the Piney Z subdivision, also the fact that Lake Piney Z has been cut off from the Lake Lafayette water system and therefore has only standing water, no movement.

Karst topography is a landscape characterized by sinkholes, streamless valleys, and streams that disappear underground. This landscape is created by groundwater dissolving sedimentary rock such as limestone. This results in the formation of different landforms such as sinkholes. Groundwater seeps into and through these landforms. If this groundwater is polluted, then the landscape is polluted.

When talking about the Floridan Aquifer, one must understand that the aquifer doesn’t negatively affect Lake Piney Z but rather that the lake negatively affects the aquifer. The Florida Aquifer is an underground system of water that purifies the water above ground. When pesticides from human activity runoff into the lake they pollute it. Since the Lake Lafayette water system contains a sinkhole, this polluted water goes down the sinkhole and directly into the aquifer.

Future of Lake Piney Z:
Lake Piney Z's best hope for recovery is the sinkhole located in upper Lake Lafayette. Currently the land surrounding this sinkhole is owned by the planned development Fallchase. Fallchase owns this land because they plan to build houses on the floodplain that is Upper Lake Lafayette. What most scientists and researchers who are monitoring Lake Lafayette want to do is to have taxpayers purchase the land around the sinkhole. There are no set plans for this purchase, but hopefully something will be worked out.

Water Testing Parameters:
On our many visits out to Lake Piney Z we tested the lake in various ways to assess the quality of the water, and its progress. We tested the water for dissolved oxygen, pH, phosphates, nitrates, and turbidity.

- Dissolved Oxygen:

Dissolved oxygen analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution. Oxygen gets into water by diffusion from the surrounding air, by aeration, and as a waste product of photosynthesis. An adequate level of dissolved oxygen is necessary for good water quality. This is so because the amount of oxygen must be sufficient to support aquatic life. The worry in Lake Piney Z is that due to excess eutrophication there may not be enough oxygen left.

- pH:

pH is a measure of the acidic or basic (alkaline) nature of a solution. The concentration of the hydrogen ion [H+] activity in a solution determines the pH. PH is a very important factor to consider in maintaining the water quality of a lake. Runoff from agricultural, domestic, and industrial areas may contain iron, aluminum, ammonia, mercury or other elements. The pH of the water will determine the toxic effects, if any, of these substances. We tested for it every time. Luckily Lake Piney Z has a very good level of pH and consistently ranges from 5 to 6. Therefore any runoff Lake Piney Z encounters has yet to effect the pH.

Nitrates are a form of the very abundant element Nitrogen. Nitrogen-containing compounds act as nutrients in streams and rivers. Nitrate reactions [NO3-] in fresh water can cause oxygen depletion. If the oxygen is depleted then the organisms, such as fish, may die. Nitrogen mainly enters bodies of water through industrial and municipal wastewater, septic tanks, or animal wastes. Bacteria in water quickly convert nitrites [NO2-] to nitrates [NO3-]. This can be potentially detrimental to the fish.

Phosphates are one of the leading causes of eutrophication. Rainfall can cause varying amounts of phosphates to wash from farm soils into nearby waterways. Phosphate will stimulate the growth of plankton and aquatic plants. If an excess of phosphate enters the waterway, algae and aquatic plants will grow wildly, choke up the waterway and use up large amounts of oxygen. The rapid growth of aquatic vegetation can cause the death and decay of vegetation and aquatic life because of the decrease in dissolved oxygen levels.

Turbidity is basically defined as the clearness of water. If there is too much unclearness then the particles causing it result in a scattering of light. If the light is too scattered then it is unable to reach the plants. This stunts the growth of plants, which sometimes provides food for fish. It also inhibits photosynthesis, which creates most of the dissolved oxygen. Obviously light is very important to the quality of aquatic life. Turbidity is an important factor to monitor.

Copyright © 2010 The Florida Geographic Alliance