Corrosion and material analysis :Student final project?

I am mechanical student doing my final project with some goverment agency about serious corrosion problems in their watergates, Here is the scenario: the watergate is control the river flow, its shutdown to stop seawater flows into the riverside when high tide. The door is made from aluminum alloy (aluminum 5XXX) is been corrode. i have a sample of bolt which same material of the door to analyst if the component is not been fabricated due to specification. The watergate is near to the agricultral area which could be polluted water. so hopefully you can tell me what to be begin with?The study case must presents the principles of corrosion, recognize the corrosion problem , determine their cause, understand and then select the control methods. principles underlying multiple disciplines, from electro chemistry and fluid mechanics to materials science and engineering. The investigation need to point out common design fault, wrong choice of material etc..contact me!! roydabest@yahoo.com