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Western Sugar Reclamation Land Development Project <br />Flood Analysis <br />remains empty during the flood. Note that this is extremely conservative because, (1) it is highly <br />unlikely that the pit will be ultimate due to the long time period of extraction (2 to 10 years) <br />needed to reach that point, and (2) it is highly unlikely that the pit will be empty. This scenario is <br />included for the purpose of predicting headcutting and erosion in the unlikely event that the pit is <br />empty. <br />Results for this scenario are summarized in Table 1 which indicate that it is possible for Tract C <br />pit to erode across the berm and back to the river for the weakest and best parameter case. <br />However for the strongest parameter case, results indicate that there will not be erosion back to <br />the river. <br />Table 1. WinDAM B Results Summary for 100 - foot -Wide Berm - Without Considering Pit <br />Tailwater <br />Parameter <br />Time -to- <br />Est Flood <br />UltimatePit <br />Max <br />Max <br />Max <br />Case <br />Headcut- <br />Warning <br />Fill Time <br />Headcut <br />Headcut <br />Headcut <br />to -River <br />Time <br />(hrs) �l� <br />Width <br />Length <br />Depth <br />(hrs) <br />(days) �l� <br />(ft) <br />at Top of <br />(ft) <br />Berm <br />(ft) <br />Weakest <br />9 <br />5 - 7 <br />15 <br />215 <br />100 <br />45 <br />Best <br />30 <br />5 - 7 <br />15 <br />155 <br />100 <br />45 <br />Strongest <br />n/a <br />5 - 7 <br />15 <br />20 <br />20 (2) <br />12 <br />(1) Discussed below. <br />(2) Doesn't erode to river. <br />4.3.2. Realistic Scenario — Includes Pit Tailwater <br />The second scenario is most realistic in that it considers that the pit will be filling due to pro- <br />actively stopping pumping by Varra Companies, Inc, and also filling of the pit due to overbank <br />flood flow. Due to such, a "tailwater," headcutting will not have the opportunity to erode down <br />the full depth of the pit. In addition and more importantly, the pit tailwater elevation will <br />eventually meet that of the floodplain WSEL much sooner than the first scenario and <br />consequently, less time is available for headcutting and erosion. <br />This scenario is still conservative in that it considers the ultimate pit. In reality, it will be 2 to 10 <br />years before the ultimate pit is achieved decreasing the likelihood of having such available to <br />headcut back to the river (from the 100 -yr flood) because direction of extraction will be from <br />P9. 8 <br />