In July 1998, Hillsborough County Water Resource Team and the Environmental Protection Commission of Hillsborough County (EPC) established and funded an independent water quality and biological monitoring program, referred to as the Hillsborough Independent Monitoring Program (HIMP).

The purpose of the HIMP is to monitor the Hillsborough River, Alafia River, Palm River, McKay Bay and the Apollo Beach area and canal system for potential environmental changes which may caused by Tampa Bay Water's (TBW) new water supply projects scheduled to begin in 2003.

The TBW projects of concern include the Tampa Bypass Canal Pump Station (with water diversions from the Hillsborough River), the Alafia River Pump Station, and the Tampa Bay Desalination plant located at TECO's Big Bend Power Plant at Apollo Beach, in southern Hillsborough County.

The County's HIMP is designed to augment TBW's required monitoring program by taking a greater number of samples of increased spatial density so that the impact of the new water projects can be analyzed more precisely and with greater sensitivity to immediate impacts.

Sample collection for the County's HIMP began in 1999, and includes three years of "pre-water withdrawal" sampling and a minimum of three years of "post-water withdrawal" sampling. Although predictive modeling for the bay and the tributaries completed by TBW indicated that the new water supply projects would not result in unacceptable environmental impacts, the County has implemented the HIMP to verify that conclusion.

The HIMP includes two monitoring elements: 1) water quality and 2) benthic invertebrates and their habitat. These elements were selected because major water quality and biotic trends appear to correspond in an ecologically meaningful manner to changes in flow and salinity, which may potentially be caused by the surface water withdrawals and the desalination plant.

The main objective of the water quality monitoring element is to estimate the distribution of water quality indicators on a temporal basis, including seasonal and annual estimates.

Critical indicators of water quality include:
· salinity (specific conductance)
· temperature
· dissolved oxygen (DO).

Potential effects of TBW's new water supply projects potentially include:
· increased salinity and pH values
· increased or decreased temperatures
· increased or decreased dissolved oxygen concentrations.

The water quality element of the HIMP has three components:
· synoptic surveys
· movable continuous monitoring
· fixed continuous monitoring.

The main objective of benthic monitoring element is to estimate the community composition (to the lowest practical identifiable taxon), abundance, and distribution of benthic macro-invertebrate infauna in the monitored areas. The HIMP has been designed to determine the extent to which the invertebrate assemblages may potentially shift as a result of TBW's new water supply projects.

Technical reports summarizing raw data collected and presented by means of data reduction, tables, and graphs have been or will be completed for the years 2000, 2001, and 2002. Comprehensive technical reports for the rivers and bay segments, for the three-year pre-withdrawal period, will be published as integrated assessment reports. These reports will be completed by mid-2003. A similar procedure will be followed during the three years of the post-withdrawal period.

The goal of the HIMP is to ensure that the flow rates in each of the rivers potentially affected by surface water withdrawals do not deviate from normal to the extent that: salinity distributions, invertebrate populations, and recreational uses are significantly altered or adversely impacted. The HIMP will focus more closely on monitoring subtle changes in salinity, particularly the potential movement of the "salinity wedge" in the Alafia River, and will include monitoring changes in water depths as well.

Because of the new Big Bend desalination facility scheduled to begin operations in early 2003, focused monitoring of water quality and benthic biota in the vicinity of the Big Bend and Apollo Beach area and at the end of the discharge canal was incorporated into the HIMP. Continuous water quality monitoring sites will be placed at the end of the discharge canal as well as in the Big Bend and Apollo Beach area.

The Hillsborough County Water Resource Team and the EPC believes the development of its own monitoring program clearly benefits its citizens by protecting natural systems from adverse environmental impacts and has a proactive effect by monitoring the environmental health of the Tampa Bay region as a whole. Additionally, by developing its own monitoring program, Hillsborough County will be able to address and evaluate TBW's monitoring program from a localized and cumulative effects perspective.

If you have questions, or seek additional information, please contact the EPC at their website, www.epchc.org, or by phone at (813) 627-2600.

Monitoring Locations ( PDF, 2677KB )