H YDRO P OWER : RENEWABLE ENERGY FROM FALLING WATER By: Kamal Badesha ology/dams/ ology/dams/

H OW I T W ORKS Dams block the water flow, the water accumulates in a valley creating a large reservoir (lake). After varying volumes the water is released through tunnels in the dam. This causes turbines to spin and this drives generators to produce electricity.

G LOBAL W ARMING The organic matter trapped on the floor of the reservoir is where the problem lies. As the vegetation begins to rot in an environment where no light and oxygen are present, full decomposition cannot occur and methane gas is released. Methane gas is more than twenty times as potent as C0 ₂.

E NVIRONMENTAL I MPACT OF H YDRO D AMS Loss of Carbon Sink: The large reservoirs flood animal habitat and also eliminate the carbon sink potential of vegetation that existed before. Release of Methane Gas: Rotting vegetation at the bottom of reservoirs is emitting huge volumes of methane gas into the atmosphere. Farmland is lost: Valley bottoms are well suited for agriculture, so when flooded valuable farmland is lost.

Erosion of Flood Plains and Wetlands: As the water level rises in a flooded valley, the potential for erosion and landslides along the steep valley side increases and much silt accumulates in the reservoirs. More Water Evaporates : In hot dry regions the water evaporates from the reservoirs. Dams Can Collapse: Reservoirs are made to store water, but the storage capacity is not infinite during the average rainfalls. As the volume of water increases the pressure on dam increases. Dams Affect Fish: Dams block natural migration routes, also they don't let spawning fish reach their spawning grounds.

M ICRO -H YDRO Energy from falling water to generate enough power to supply a factory or a small community.

R UN - OF -R IVER LESS DAMAGING TO ENVIRONMENT No large reservoir needed to store water. Nutrient rich sediment is not blocked off. No need for massive concrete dams.

O PPORTUNITIES NEARLY LIMITLESS Smaller hydro projects can supply about 500 homes or a community. Better because you can use the water from mountain streams. Large hydro projects can only be constructed in a few remote locations.

A DVANTAGES OF R UN - OF -R IVER H YDRO P OWER No animal habitat needs to be flooded. No valuable farmland is taken up by a large reservoir. Provides a localized power source for remote communities. No need for large power transmission lines.

Does not block fish from reaching spawning grounds. Not easily damaged by violent weather events. Cheaper than large scale hydro projects. Replaces dirty fossil fuels that create air pollution. Does not produce acid rain. Does not take part in the effect of greenhouses. Water volume in river remains the same when water intake and power house are close together.

D ISADVANTAGES OF R UN - OF -R IVER H YDRO P OWER Small streams may dry up during the dry season. Power potential is limited. Too many power facilities in one area can do major damage to wildlife populations and local fish. Too much water causes fish to not reach spawning areas. Power plants cause water levels to change rapidly and result in stranded fish.

V IDEOS + E XTRAS project-can-affect-a-river/