I don't know about hilly areas (many stations are next to dams), but they have to be built where the water flows through the turbines by gravity (i.e., does not have to be pumped).
2 hydroelectric dams in south Africa
Wisconsin uses cars, busses, aircraft, and trains as transportation. There are also many people in the cities that choose to walk or ride bicycles. Snowmobiles are also very popular in some areas.
the answer to your question is that OVER 9000! people work in a hydroelectric powerplant.
69 ;)
There area little over 850 Hydroelectric Power plants in the United States
there is approximatly 259 to 367 barrels pumped per day. :)
850
1,000,000 houses
36
12
10