Technical Manual: Conduits through Embankment Dams (FEMA 484)

Chapter 9—Inspection and Assessment of Conduit-Related Problems9.8.6 Reservoir water level and flowsThe reservoir water surface level is a key item to record when measuring otherinstrumentation at a damsite and should be measured and recorded each time theembankment dam is visually inspected, and when other instrumentation is observedor read. The reservoir water level is also used when evaluating the informationprovided by the other instruments at the site. For instance, the amount of seepageexiting the embankment dam as it relates to reservoir water level is often crucial. Apattern of increasing seepage at the same reservoir level is cause for concern. Waterlevels may be measured by simple elevation gauges, such as a staff gauge or numberspainted on permanent, fixed structures in the reservoir, or by complex water-sensingdevices. Reservoir flow release quantities are often computed from the depth offlow in the conduit or exit channel or by predetermined conduit discharge ratingtables/curves. During an emergency, it is important to monitor the water level in thereservoir and the downstream pool regularly, along with the quantity of water beingreleased from the embankment dam’s outlet works and spillway.243