Laserfiche WebLink
and devastation. The Dam Safety Branch used the best available tools and methods, within <br />available resources at the time of this study to analyze and report on the flood event in hopes of <br />helping explain the causes and effects of the flood damage experiences during the September <br />2013 event. <br />►M1.3ICU141 VJ:1410129:14ATJ4011111 <br />The rainfall and resulting flooding of September 8 -18, 2013, was the result of a large scale <br />weather system that was not unprecedented, but was historic. It has been reported (Doeskin, <br />2014) that this storm ranked in the top three of extreme storms documented in Colorado. By <br />most accounts, the rainfall and flooding occurred simultaneously from El Paso County in the south, <br />to Larimer County in the north. The first reports of flooding impacting dams came at 2:11 am MST <br />on Thursday September 12, 2013. Larimer County emergency managers issued warnings and then <br />sent requests for assistance in response to rainfall and flooding in the headwaters of the Little <br />Thompson River between Estes Park and Berthoud. By the time the sun rose on September 12, <br />emergency response agencies from Colorado Springs to Fort Collins were in full response mode as <br />all levels of responders raced to get impacted citizens out of harm's way. Figure 2 shows the <br />extent and magnitude of the rainfall event. <br />Total Stonn Precipitation (inches) <br />September 8 (800 UTC) - September 18 (700 UTC), 2013 <br />24 -hour Precipitation (inches) <br />-0 -8.25 2.0 -2.5 -10.0 -12.4 <br />®r�0.25.0.80 O2S -3.0 -12.0.18.0 <br />}... aP u 0.50 -0.75 ® 3.0 -4.0 O 15.0. -20.0 <br />�0.i5. 1.0 Q4.0 -6.0 20.0 <br />_ Di.0.1.5 -6.0.8.0 <br />i- liamd — 1.5 -2 -0 111♦8.0 10.0 <br />GRGS 191N <br />ry M a SyN m 'N <br />j R ' �V+` ;/ Lo�q Iudna15[ah DAq WGS 1904 <br />Cocf <br />v fiAife$ p u°[s. ce <br />.—— 0 25 50 <br />w Boulder inset.",-, =' -`s _ <br />Fort i II l f a' /� . `I . <br />f� <br />Cr r <br />Colorado 5}]ring5 JrFSet <br />{fir <br />DO <br />11 7 r 1 J' <br />Figure 2 — Map of total rainfall from September 8 -18, 2013 Storm (Applied Weather Associates, 2014) <br />Report of the September 2013 Little Thompson River Flooding COLORADO <br />and Big Elk Meadows Dam Failures, June 2014 (Revised, Dec 2014) Division of Water Resources <br />Page 2 of 48 D pjrtm._n1 of r.a1urar s,,,Gurc�, <br />DAM SAFETY BRANCH <br />