It could be a bad ground connection at the block. Since you have just replaced the water pump, you might check the ground at the block. Does the wire going down to the starter get hot or seem to jump around when you are trying to start it? If so, the starter could be shorted. With the car in park and the e-brake on, you can jump across the solenoid to start if the solenoid is bad.
Eleanors, the red Camaro of a new generation....
65 Ranchero - Will be my new daily..hopefully
65 Fastback - Screaming Yellow Retro 65 B/FX
66 Pony GT Coupe - Emberglo 4-speed
67 K GT Coupe - Bench seat 4-speed..in pieces
95 Lightning - Vortech, Bassani's,Pro-M