Laserfiche WebLink
<br />6) Dam Slopes Design: 2.SH:].OV. Measured: Outslope 2.SH:1.OV with large rock (>24" <br />diameter) placed neaz gulch. Inslope: 2.SH:l.OV. The slopes were solid in all locations <br />and showed no evidence of erosion or gullying of any kind. <br />7) Pond Denth Design: 15.0 ft. Measured: 15.9 ft. Water level was approximately 1.5 feet <br />at the time of the inspection. <br />8) Rio Rap Linine in Emereencv Snillwav Design: 12" thickness of 10" to 12" rip rap, <br />durable rock. Measured: 12" thickness of 10" to 12" rip rap, durable rock. <br />9) Sediment Storage Volume: Design: 0.22 acre-feet. Measured: 0.4 acre-feet. <br />10) Storm Detention Volume: Design: 4.08 acre-feet. Measured: 4.1 acre-feet t 4%. <br />11) Ri~ra~at Discharge of Principal Spillwav: Design 8" diameter durable rock. <br />Measured: as designed. <br />12) Sloe Stability There was no evidence of seepage anywhere along the outside of the <br />embankment or the principal spillway pipe although the pond did contain water. There <br />was also no evidence of cracking, bulging, slipping or other signs of slope instability. <br />Vegetation was excellent on the top of dam and all sidelsopes. Previous compaction tests <br />done on the dam material were within specifications. There was no evidence of freeze <br />thaw action at any point along the embankment. <br />As a professional engineer experienced in embankment slope stability design, construction <br />and maintenance, I am confident that the dam meets the long term slope safety factor of <br />1.3. In fact, past experience indicates that the slope safety factor is most likely above 2.0. <br />It is stable for the following reasons: <br />-the reconstructed slopes are 2.SH:1.OV, which is mild for a small pond with a height <br />less than 10 feet. <br />~'~~ -there are no weak spots in the original ground or springs or seeps which could interfere <br />„ab~oi with stability. <br />W"k ~ -the principal spillway has been properly compacted so that piping will not occur. <br />j3~ ~~~ <br />0 -the dam has been constructed in lifts with proper compaction as the independent data <br />shows. <br />