Elementary profile of a given dam is only theoretical profile. Certain changes have to be made in this profile in order to cater practical needs.

These needs are:

(i) Providing a top width for roadway construction.

(ii) Providing a free board over top water surface.

• These additions of two provisions will cause the resultant force to shift towards heel.
• The resultant force when the reservoir is empty was earlier passing through the middle third point.
• This will therefore shift more towards the heel, crossing the inner middle third point and consequently, tension will be developed near this.
• In order to avoid tension, some masonry or concrete will have to be added on upstream side as shown in the figure which shows typical section along with possible dimensions that can be adopted for low gravity dam.
• It should be checked for stability analysis.