Groundwater Managment
Understanding the hydrology and ecosystem of the Cone Ranch Wellfield project area is essential so that potential wellfield configurations can be evaluated and developed in a manner which would protect the rights of existing water users, protect the environment and be consistent with regulatory requirements.
The following graphic depicts the hydrologic cycle and shows how water enters the cycle as rainfall and exits the cycle through evapotranspiration, streamflow, recharge to the aquifer system, groundwater outflow and groundwater pumpage. The quantities of water shown in inches represent and average approximation of how water moves through the system in a typical year. The movement of water within the cycle changes from year to year as rainfall, climatic conditions and groundwater withdrawals very. Techinical evaluations conducted fro the Cone Ranch Wellfield project consider how additional groundwater pumpage in the Cone Ranch area may affect local water levels and existing area water users.
A more stringent permitting process also ensures sustainability of our natural resources. While the previous permitting process only relied upon short-term model simulations (three to four months in some cases), multi-year simulations are used today. Additionally, the Southwest Florida Water Management District, which issues water use permits, is developing rules on minimum flows and levels to protect existing water resources from being over-utilized. Tampa Bay Water's focus is on long-term hydrologic and ecological sustainability.This scrutiny should prevent history from repeating itself.
SWFWMD Permitting Criteria
Permitting rules of the SWFWMD require that Tampa Bay Water demonstrate that the proposed water withdrawals will not result in water quality or water quantity changes that adversely affect the water resource. Water withdrawals are not permitted to adversely affect wetlands, lakes, streams, fish, wildlife or other natural resources.
Current water use permit rules and basis of review criteria adopted by SWFWMD in 1989 (Chapter 40D-2 FAC) include:
- The use is necessary to fulfill a reasonable demand
- Will not cause quantity or quality changes which adversely impact the surface and groundwater resources
- Will not cause adverse environmental impacts to wetlands, lakes, streams, estuaries, fish and wildlife or other natural resources
- Will not cause water levels or rates of flow to deviate from minimum flows and levels
- Will use the lowest quality water the applicant has the ability to use
- Will not significantly induce saline water intrusion
- Will not cause pollution of the aquifer
- Will not adversely impact offsite land uses existing at the time of the application
- Will not adversely impact an existing legal withdrawal (this includes both private domestic wells and permitted wells)
- Will utilize local water resources to the greatest extent practicable
- Will incorporate water conservation measures
- Will incorporate reuse measures to the greatest extent practicable
- Will not cause water to go to waste
- Will not otherwise be harmful to the water resources within the District
- Proposed changes to the MFL rule resulted from environmental and hydrologic studies which began in 1989
- The MFL rule provides a higher level of environmental protection than existed previously
- Through the MFL approach, site-specific review criteria can be developed for the protection of wetland and surface water bodies.
- MFL approach will be applied to the Cone Ranch and Dispersed Wells project as part of the basis of review
- Minimum flows are proposed to be set on the Upper Hillsborough River system in 2006
- Minimum levels have been established for wetland on the Cone Ranch site
In the Tampa Bay area, we have learned a great deal about protecting sensitive ecosystems to ensure that water supplies will be available in the future. This concept of "sustainability" is why Tampa Bay Water has placed great emphasis on new environmental technologies.
Despite all the improvements in predictive modeling, science is still inexact in some situations. Not everything can be pre-planned. Therefore, assumptions must be confirmed through tracking and monitoring. Then operations can be adjusted to respond to actual conditions.
As a condition of its water use permits, Tampa Bay Water has included extensive hydro-biological monitoring programs in its new water-supply projects, such as the monitoring program developed for the Alafia River, Hillsborough River and Tampa Bypass Canal. Representatives from several organizations helped develop these programs, including the Hillsborough County Environmental Protection Commission and the Southwest Florida Water Management District.
Tampa Bay Water's goal is to meet our region's water needs while protecting our environment for the future. With new technologies to more accurately predict and extensive monitoring programs to track the effects of new supply sources, that goal will be met.
