If the water is gushing from the washer, check the small plastic air dome hose on the lower right hand side of the wash tub. Sometimes the hose can come loose and come off. This will cause the water to begin pouring out of the bottom of the the washer when it begins to fill. The following link lists some other items you may consider as well:http://www.fixya.com/support/r3576648-washer_leak__top_loader
The link explains how to remove the exterior washer case in order to accurately inspect the washer interior components for the source of your leak.
If the leak is more like a constant drip, another common source of leaks with Whirlpool manufactured top loaders is a leaking drain pump. These pumps are not serviceable and if damaged, must be replaced. The following link explains how:http://www.fixya.com/support/r3794382-replacing_water_pump_whirlpool_top
Don't forget to check all drain hose connections under the washer and the center tub seal.
Replacement parts (if required) can be purchased at any of the following websites:
Prices vary between sites, so shop and compare. the first three sites listed also have helpful exploded view parts illustrations to assist you with locating and properly identifying the parts you may need.
If you have any questions, please post back and let me know. I hope this helps you.
NOTE: Roper washers are manufactured by Whirlpool, so these instructions will apply.