PAES IRRIGATION STRUCTURE Flashcards
volume of water stored in reservoir between the minimum water level and
normal water level
Active Storage
vertical distance from lowest point of the ground line to the dam crest
Dam Height
volume below the intake structure computed
Dead volume
dam component which prevents migration of small particles and screen off fine
materials that flow with seepage water and prevent piping
Filter drain
maximum elevation the water surface which can be attained by the dam or
reservoir without flow in the spillway
Normal Storage Elevation
vertical distance measured from the top of the dam down to the bedrock
Structural height
The stable slope for the upstream face is
2.75:1
The stable slope for the downstream face is
2.5:1
actual height of the embankment after settlement
Design height
height of the embankment to be attained during construction
Finished height
ratio of the storage capacity to the total earth volume required for embankment
construction which indicates the relative cost of the different types of reservoir
Storage ratio
rainfall pattern with five wet months of more than 200 mm/month, five dry
months of less than 100 mm/month, two transition months of 100mm200mm/month and total annual rainfall above 1500 m
Unimodal rainfall pattern
Suited to an area with an
undulating topography. A
dam is built across a
valley and water is
impounded on the
upstream side of the dam
Straight embankment
On slightly sloping land,
the excavated earth can
be used to impound some
water above ground level.
On higher slopes, it can be
designed so that all water
is stored above service
level
Rectangular balance equation
Water is impounded
against the slope behind a
semicircular
embankment
Semicircular embankment