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MEMNON A. M. ENGINEERING AND TESTING, INC. Geotechnical Exploration for Stormwater Management Planning Indian River County Parks Maintenance Complex , IRC Project No . 0710 A. M. Engineering Project No. PSL 1825 -2 inches of the ground surface for 1 up to 4 months per year. The Soil Survey describes Po sand, 0 to 5 percent slopes as a nearly level to gently sloping and moderately well drained smello generally at oil on low ridges and knolls on the flatwoods. The water table with unimproved drainage is a depth of 24 to 40 inches for about 1 to 4 months during the wet season. The three soil profiles generally consist of fine sand with little silt to depths of 6'/a feet. The soil profile for Myakka fine / to 43/4 feet, sand includes a layer of weakly cemented sand with trace to little silt at a depth of 4' and the soil profile for EauGallie fine sand includes a layer of sand with some silt and clay at a depth of 4 to 5 %4 feet. SFWMD WATER MANAGEMENT DISTRICT RAINFALL INFORMATION The rainfall has been considerably lower than normal during the three months prior to our explorations . According to the SFWMD the rainfall in Martin and St. Lucie Counties during the 30 days prior to April 10, 2007, was 41 percent of the normal; during the 30 days prior to March lM 2007, the rainfall was 15 percent of normal; and during the 30 days prior to February 10, 2007, it was 18 percent of normal. Furthermore, a news release from the SFWMD (January 4, 2007) indicated that despite above average December rains , 2006 ranked as the sixth driest on record. The Martin/St. Lucie Basin received only 61 percent of the expected historical average rainfall . „\ gg DISCUSSION AND CONCLUSIONS 1 The subsurface soils encountered in the auger borings corresponded well with the information presented in the Soil Survey. The recent rainfall history indicates that the observed water table levels are lower than normal. I Ground water and surface runoff will tend to flow towards the site and the canal since they are located in the low area paralleling the coastal ridge. The presence of the Lateral "G" Canal adjacent to the proposed pond and the pervious nature of the soils underlying the pond area indicate that the actual wet season water table levels will be strongly influenced by the water level of the canal . a Based on the above data and the results of our field exploration , we estimate that the average wet season high water table level is I foot or less above the level of the Lateral "G" Canal . However, should rainfall intensity and duration or total rainfall quantities exceed the normally anticipated rainfall quantities, the groundwater level may exceed our estimate of the average wet season high groundwater level . LIMITATIONS This report is for the exclusive use of the Indian River County Engineering Department in the design and construction of the previously described project. The right to rely on this report may _ not be assigned without written permission of A. M. Engineering and Testing, Inc. F 3