yeah. i can list a few.but mind you i'm just in my second year and can make a lot of mistakes.just trying to put forth some points learnt last semester in my applied geology.
1.the dam should be built in the course of the river at a point where it's
width is less.
2.the site should be as sturdy as possible and should be made of
strong, impermeable rocks
3.the materials should be available close by.it will reduce the cost to some extent.but this is not the most important factor.
4.all dams do cause the environmental hazards like loss of cultivable land, loss of forests,etc. but a dam should be designed to
reduce the impacts on environment.
5.the
dip of the surface should also be studied.
6.and the dam should never be built on a area where there are
folds.(shown in the figure below. the anticlines and synclines are folds).it leads to the movement of the structure
7.the dam
should not be built on the area of fault.fault is the breaking of the earth surface.it will lead to the seepage of water into the earth.
there should also be no joints.
the four main faults are shown in the figure below.
the dam should not be built on these area.but if it is absolutely necessary to build a dam in that spot.we have to build it only in a reverse fault region with the fault along downstream direction .
that's all i could recollect.will get back with more points😁