Kanapaha Prairie, 1994 PUD Proposal,Conservation Element, Policies and Objectives,
Pearson Sink, Flooding, 100 Year Flood Plain,
Weather, DRC
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To the Honorable County Commissioners,On Tues, May 28, 2002, during the morning meeting, the BOCC will consider the matter of the Pradera plats. The DRC voted to approve, but, at the request of citizens, sent it as an item on the regular agenda instead of the consent agenda. The proposed plat and permit will affect one of the most sensitive natural systems in the county. Some current members of the commission might not be aware of the history, geology or hydrology of the area and, hopefully, will find the following information useful. Most of the information re: the prairie was found in a 1986-87 CH2MHill study evaluating GRU's plan to spread sludge on Levy Lake. It was determined that should not be considered because of the danger to the aquifer in such a sensitive area. Kanapaha PrairieKanapaha Prairie is located south of Gainesville just west of Williston Road. The subbasin includes approximately 3,867 acres of land. Approximately 1,500 acres of surface area is open pasture or marsh, and is called Kanapaha Prairie. Geographically, it is close to Paynes Prairie, but hydrologically, it is entirely different because Paynes discharges water into the Alachua Sink, while Kanapaha is drained by the PearsonSink. (See Pearson Sink below.) Kanapaha Prairie drains a 41 square mile area, and leads directly into the Floridan Aquifer - the source of drinking water for thousands of people. Most of the water comes from direct rainfall and from Levy Lake, a large, shallow area south east of Kanapaha. Levy collects water and sends it via stream-to-sink under Williston Road (SR 121) The dry natural stream bed can be observed from the road even during droughts. 1994 PUD ProposalIn 1994, Mr. David Miller, Kanapaha Realty, submitted a plan to develop approximately 1,100 acres. The plan requested a zoning change to a PUD, with development clustered on the upland, but with Transfer of Development Rights from over 600 acres of wetland. The plan asked for 219 homes, with 219 septic tanks. It was brought before the BOCC for approval in Oct., 1994, with the Staff recommending approval. After two meetings in which citizens voiced many objections based on parts of the comprehensive plan that had not been applied by Staff, the BOCC had a very dramatic vote just before 1:00 am (by then Dec,7, 1994). They found, 3-2, that the PUD was "inconsistent with the comprehensive plan." There were several inconsistencies, but one of the main reasons given was their great concern for the safety of the quality of water going into the aquifer and then to private wells. The decision was upheld in both circuit and appeals court. In fact, the appeals court in Tallahassee even refused to hear oral arguments. Since that time, the owners have used the area for agricultural purposes. At present, it is being used for cattle grazing. Conservation Element UsedListed below are some parts of the Conservation Element, County Comprehensive Plan (1991), considered by the BOCC for their deliberation and finding that the proposed development was inconsistent with the comprehensive plan. Policies and ObjectivesPolicy 2.3.16 states unconfined areas need special protection from wastewater, especially in recharge locations. (Pearson Sink) Objective 2.6 Soils and Slopes 2.6.1 soil suitability must be considered. The Kanapaha soil is porous sand, the aquifer is unconfined and close to the surface (See pictures of the Pearson Sink), allowing immediate infiltration into the water supply used by so many private wells in south west Alachua Co. Objective 8 applies to areas containing special resources or providing special functions requiring protection, such as sinkholes. Objective 8.1 Kanapaha Prairie contains Pearson Sink, an important recharge area directly into the Floridan Aquifer. Policy 8.4.4 provides that septic tanks and drainfields shall be sited in a manner so as to protect conservation areas from the discharge of improperly treated effluent. Septic tanks are not efficient in the porous conditions that exist in the area. Though not cited here, the BOCC was also concerned about the level of services such as fire and police with long transit times, crowded schools and no public transportation. *Another important issue was the potential for flooding and contamination from septic tanks.* Also of concern was conservation of habitat for protected species, including Sandhill cranes who need undisturbed uplands on which to teach their young to forage. MapsProtected Areas and Significant Natural Upland Communities -Shows Kanapaha as #18 on a list of 29. (In a later map, Kanapaha is listed as tied for 9-12 on a list of 18 protected areas.) Map 8 Aquifer Zones - Kanapaha is located in the unconfined zone. (The map included in the proposed comp plan shows the same.) Map 11 The Pollution Potential of the Floridan Aquifer - Shows Kanapaha is located in an area that allows immediate infiltration, so potential for pollution is high. TablesTable12 Soil Associations of Alachua Co showing degree of limitation, suitability and potential for selected uses - #6 includes Kanapaha and lists the limitation for septic tanks and building sites as "severe." Pearson Sink
The key to the entire system is the Pearson Sink - pictures at: http://www.afn.org/~thescore/pearson.html which is located in the north western part of the prairie. The flow of surface water is generally north west from Levy Lake. When the water flows into the sink, it enters the Floridan Aquifer which flows generally south west. Eyewitnesses have described the action of the sink as being like a bathtub; draining most of the time, but with an occasional clog. Such a clog might have contributed to the 1998 flooding. (See Flooding below.) FloodingThe prairie has a known history of flooding at intervals of only 10-15 years, much more frequently than the "100 year flood plain" designation would imply. The last flood (1998) was more noticed because of the number of homes built along the prairie. Many of the owners did not have flood insurance because they had been told the land was above the 100 year flood plain. Even though we did not have extended heavy rains, the flood waters rose for months. It was discovered that dams in Levy Lake, and the pumps that served them, were constantly sending more water into the prairie via the stream-to-sink discussed above. Pearson Sink was not able to drain fast enough. Of crucial importance is that the development level currently along the prairie is not intensive; most of the lots are at least 20 acres. *However, the septic tanks caused dangerous levels of bacteria in the wells for months.* (You will see video of TV 20 coverage.) Wells, geographically over a mile from the floods, suffered effects, such as red-colored or foul-smelling water flowing from faucets. The residents of the various Farms of Kanapaha were frantic and helpless to stop the water only inches from their homes. They had to use canoes to get around. Convict labor was enlisted to help with sandbags to keep the water from ruining homes. (On Tues, you will see video of the problem.) The county commission had to pay well over $30,000 to the Ramsey family to send some of the Levy Lake water onto the Ramsey land. St. Johns Water Management District has not been able to solve the underlying conditions. When the rains come roaring back, the floods will also. 100 Year Flood Plain
A map, not site specific, that locates areas in which owners should buy flood insurance, explains what the term 100 year flood plain means. It actually means that there is a one in a hundred chance that a given site will flood in a *single* year - not in 100 years. An online source gives the same information:
WHAT IS A 100-YEAR FLOOD PLAIN? A 25-YEAR FLOOD PLAIN?If your property is in the 100-year flood plain, there is a 1-in-100 chance in any given year that your property will flood. If it is in the 25 year flood plain, there is a 1-in 25 chance in any given year that your property will flood. The statistical chance of flooding is not changed by any one flooding event; but repeated flooding may result in the flood plain being recalculated. A 100-year flood plain is always wider than a 25 year flood plain, and the 25 year flood plain is contained within the 100-year flood plain. ***** To a statistician, it is probably clear, but to most people, it conjures up a false sense of security. If a person purchases a site that just flooded in 1998, it would be easy to believe that it likely would not flood for another 95 years. In fact, it means there is a 50% chance of a flood in any following year or several consecutive years regardless of past records. Insurance companies seldom lower rates following a flood in a 100 year plain. WeatherThis area has not experienced major impact from a hurricane, dumping 10-12 inches of rain, in decades. There have been periods of heavier than normal rain that have resulted in floods, but the rain in 1997-98 was not that unusual. The IFAS web page has an archive of rainfall.
El Nino is going to form, and hurricane predictors say there will be at least 6 major hurricanes this season. El Nino reduces the chance of hurricanes coming in from the Atlantic, but ones that form in the Gulf tend to be stronger. DRCThe DRC voted to permit the proposed development because it has been carefully crafted to fit within the letter, if not the spirit, of the regulations. DRC has no quasi-judicial authority. but the BOCC does and can make decisions that serve a useful public purpose. The quality of our water is certainly that. And there are other options. Respectfully submitted for the public record by: Ellie Schwab |