Item 8EAGENDA ITEM # 8E
OCTOBER 13, 2008
CITY OF ATLANTIC BEACH
CITY COMMISSION MEETING
STAFF REPORT
AGENDA ITEM: Technical Symposium on Withdrawals from the St. Johns River
SUBMITTED BY: Donna Kaluzniak, Utility Direct
DATE: October 2, 2008
BACKGROUND: On September 17 - 18, 2008, staff attended a symposium held by the St. Johns
River Water Management District (SJRWMD) for the scientists investigating potential cumulative
effects of surface water withdrawals from the St. Johns and Ocklawaha rivers.
This multi-yeaz, $2.1 million project will include 50 scientists with national standing, working in
seven workgroups:
• Hydrodynamic and Water Quality Modeling
• Biochemical
• Nutrients & TMDL
• Benthic Macroinvertebrates (aquatic insects and crustaceans)
• Littoral Zones (aquatic plants)
• Ichthyofauna (fish)
• Wetlands
Phase I of the project, a course analysis, was recently completed, with some of the results discussed at
the symposium. Phase II will be a 23-month effort to refine the analyses started in Phase I.
The entire study will be peer reviewed by the National Research Council, the research arm of the
National Academies, which serve as advisors to the nation on science, engineering and medicine.
Some results of the course analysis:
• Modeling is complete with excellent calibration
• The average flow of the St. Johns River is 5.2 billion gallons per day.
o Maximum 7-day avg. in September 2004 was 36.6 billion gallons per day
o Minimum 7-day avg. was a negative flow in May 2002 of 882 million gallons per day
• At the maximum proposed water withdrawal the greatest change in the river's level would be
1.4 inches.
• At the maximum proposed water withdrawal the greatest change in salinity would be 0.7 parts
per thousand. (20 ppt is considered marine water). In comparison, channel dredging will have
a maximum impact of 2.2 ppt.
AGENDA ITEM # 8E
OCTOBER 13, 2008
The scientists are now embarking on Phase II of the study. More information and copies of the slide
presentations from the symposium are available on the SJRWMD's web page. Go to
www.sjrwmd.com and click on "Surface Water Withdrawals -Get the Facts."
BUDGET: No budget impact. For Commission information only.
RECOMMENDATION: Staff will continue to monitor the results of the study.
ATTACHMENTS:
REVIEWED BY CITY MANAGER: