(iii) Climate It is generally difficult to handle fine-grained soils during the rainy season and control the construction moisture content of the fine-grained soils in arid regions. As such, if the construction of the embankment has to be carried out during the rainy season, it is advisable to have sloping core embankment. Similarly, in arid regions, one extra year may be required for constructing a small reservoir for storing flood runoff for the purpose of construction of the dam.
(iv) Shape and Size of Valleys A dam site with broad valleys and gently sloping abutments may not affect the design of an embankment. However, narrow valleys and steep abutments may necessitate special design provisions. For example, because of the limited working space in a narrow valley, a simpler design requiring few special construction provisions is preferable. If the construction and maintenance of haul roads on the abutments at different elevations become difficult and costly,
492 IRRIGATION AND WATER RESOURCES ENGINEERING
one may have to design a rock-fill embankment which can be constructed by dumping rock in high lifts from relatively few haul roads.
