Managing your water project effectively goes beyond hiring the right water engineers. You need experts in finance to ensure the projection does not overshoot the budget you have made for it. In fact, water project management involves a number of experts and professionals at different stages of the project. You should understand this clearly so that you let each expert play his or role to complete the job.
In cases where the project is likely to go above the anticipated cost, the smart move is to reach an agreement on contract review. It is always better to get an excellent project that costs a bit more than to insist on a cheap but shoddy job. In any case, it is common for water projects to run into additional costs. It is better you anticipate this and plan for it so that it will not come as an unpleasant surprise to you.