Drainage patterns on and immedi- 

 ately adjacent to the proposed Unit 

 24/Unit 30 development site were al- 

 tered by early (1926) railroad con- 

 struction, early highway construction 

 (Belle Meade grade) , drainage ditches 

 (adjacent to State Road 92 and Port 

 au Prince subdivision), golf course 

 and airport construction, and by 

 agricultural drainage practices. On 

 a local basis these factors raised 

 the water table in some areas creat- 

 ing probable vegetation changes from 

 saline to fresh. In other areas 

 these factors channelized surface and 

 groundwater flows directly to the 

 estuary resulting in certain fringing 

 estuarine areas being cut off from 

 historical freshwater flows. In 

 addition, the channelized flows 

 changed the timing and quality of 

 freshwater inputs to the estuary. 



The proposed plan for restoring 

 freshwater inputs to the estuary is 

 based upon blocking all channelized 

 flows that presently leave the site. 

 Real estate lakes will be constructed 

 in uplands and in impacted freshwater 

 wetlands immediately upgradient from 

 the estuary. Lake excavation mater- 

 ials will be utilized to fill adja- 

 cent areas for roads and dwellings. 

 A low levee will isolate the lake 

 from the estuary. Water levels in 

 the lake will seasonally vary between 

 +1.5 and 2.0 (NGVD) duplicating pre- 

 sent water table fluctuations. The 

 lake will be fed by rainfall, surface 

 runoff from adjacent development 

 areas, and by groundwater inflow. 

 The lake will discharge by evapora- 

 tion, groundwater outflow, and over 

 adjustable weirs to spreader ditches 

 which will overflow into preservation 

 estuarine wetlands. Freshwater out- 

 flow from the lake will thus be de- 

 livered to the estuary via sheet flow 

 across preservation wetlands. Up- 

 gradient surface flows from offsite 

 will be routed via grassed swales 

 around the development and supplied 



to spreader ditches and then via 

 wetland sheet flow to the estuary 

 (Figures 6 and 7) . 



In this particular area of 

 Florida there is a natural berm near 

 the water's edge. This berm causes 

 shallow impoundment of extensive 

 areas. The berm is overtopped by 

 high spring tides. The shallow im- 

 pounded area is therefore filled by 

 rainfall, surface runoff from upgra- 

 dient, and by overtopping spring 

 tides. Surface discharge from the 

 man-made lake will be supplied via 

 spreader ditches into this shallow 

 natural impoundment. Slow migration 

 across this impounded area to the 

 estuary will allow polishing and 

 treatment of outflows prior to 

 arrival at the estuary. 



All the real estate lakes will 

 be interconnected allowing the flexi- 

 bility of routing surface discharge 

 to the adjustable weir and spreader 

 ditch immediately upgradient from 

 particular fringing wetlands that can 

 be improved by freshwater inflow. 

 The lake system is designed to ini- 

 tially retain a 100-year, 24-hour 

 storm. Weirs will be adjustable to 

 allow subsequent discharge over a 

 protracted period thus simulating 

 historical freshwater inputs to the 

 estuary. During dry periods ground- 

 water inputs to the lake will be rou- 

 ted to spreader ditches and then to 

 wetland surface flow instead of lost 

 to drainage ditches as at present. 



CONCLUSION 



This project is not intended to 

 set a precedent for wetland develop- 

 ment. The goal is to achieve a com- 

 promise where changing government 

 regulations have halted an ongoing 

 project. Development of 1,500 acres 

 of uplands and 2,500 acres of 



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