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SCOPE <br /> This report presents the results of our geotechnical investigation for the Levee <br /> at Deepe Farm Pit located southeast of the intersection of Highway 36 and Table <br /> Mesa Drive in Boulder, Colorado (Fig. 1). Our purpose was to evaluate the levee and <br /> compare the results to the Federal Emergency Management Agency (FEMA) design <br /> criteria for levees. This report includes descriptions of the subsoils and ground <br /> water conditions found in our test holes and test pits, results of our field permeability <br /> tests, and our evaluation of the levee at the critical section for slope stability, <br /> seepage and settlement. The summary of our findings and conclusions is presented <br /> below. Detailed descriptions and results of our analysis are presented in the <br /> remainder of the report. <br /> SUMMARY OF CONCLUSIONS <br /> 1. Results of our investigation indicate the levee meets FEMA design <br /> criteria for slope stability and piping through or under the levee. <br /> 2. The soils penetrated by our test holes and test pits drilled from the <br /> levee crest were 5 to 10 feet of dense, clayey, gravelly to cobbley sand, <br /> levee fill. The foundation soils below the levee were mostly dense to <br /> very dense clayey, gravelly to cobbley sands with occasional layers of <br /> stiff to very stiff sandy clays. Claystone bedrock was encountered in <br /> one test hole at a depth of 16 feet below the levee crest. The subsoils <br /> exposed in the test pits that were excavated on either side of the levee <br /> crest were dense to very dense, clayey, gravelly and cobbley sands <br /> and very stiff, highly weathered claystone bedrock. Free ground water <br /> appeared in three of the holes drilled from the levee crest at depths <br /> between 11 and 13 feet and in 4 of the holes excavated on the sides of <br /> the levee at depths between 3.5 and 4 feet during drilling. <br /> 3. Judging from our observations, we believe the levee fill is densely <br /> compacted. In our opinion, the foundation consolidation has occurred <br /> due to the weight of the original levee. The proposed 2.4-foot <br /> maximum levee raise will add little additional weight to the existing <br /> levee so no noticeable loss of freeboard is expected. <br /> FLATIRONS COMPANY <br /> LEVEE AT DEEPE FARM PIT <br /> CTLR 25,385 1 <br />