a. Fluctuation of water levels behind the dam
b. Negative impact on fisheries
c. The formation of a huge lake behind the dam
d. Reduction of oxygen in water
e. Water stagnation and contamination behind the dam
f. Obstruction of navigation in the course of the river
g. Obstruction and accumulation of silt behind the dam
h. Huge costs for building dams
i. Political problems for building dams
j. The danger of dam collapses
1- By using this device, it is easy to overcome all the side effects that result from building dams in addition generation the same amount of power if not more which requires building a dam.
2- The device is designed in a way that satisfies the demands of the laws of physics and liquids.
3- It doesn't block navigation across the stream course.
4- It produces clean energy and environment friendly.
5- It is a great cheep renewable resource of energy.
6- It doesn't need lots of facilities for manufacturing the device.
7- Easy maintenance.
8- The device can be fixed over spillways of dams or water gateways, over a flume or as a floating object also over gateways or even as a stand alone unit.
9- It can be fixed across the width or the length of the water stream.
10- It is easy to fix.
11- It doesn't need to be moved to a different location for mentainance.
12- It is a stable source of energy when compared with wind energy.
13- It helps to increase O2 in water.
14- It doesn't have any negative side effect in the water stream such as producing aggressive current that sweeps the soil ( the distances between the paddles in the device solved that problem).