Installation manual

Some ideas for intakes made from scrap stainless steel components

4.8.1. Water usage with minimum impact on the environment

Micro-hydro systems may potentially affect:

 Plants and fish in the water.

 Plants and animals beside the water.

 Stream banks and surrounding land.

You must check with your local authorities to see if you need to obtain consent either to build

any structures or to take/return water from a waterway. The impact of your system on stream

ecology will usually be considered during this process. EcoInnovation have some consent

application examples for NZ that we can email you that might help in your application.

Most micro-hydro systems divert a fraction of the main water flow through an intake screen

to the generator. A good intake will lead to negligible erosion and the screen will minimize

the chance of fish, leaves, etc entering the supply pipe. Taking less than 50% of the

minimum seasonal flow rate in your water source means there is no impediment to fish

moving up or down stream and hence gives aquatic life a better chance to survive.

You should take care to ensure that the exhaust water from the turbine can return to the river

without scouring the bank of your waterway. Line the bank with concrete, timber or plastic

sheet as required. Some systems utilise the exhaust water for irrigation, allowing the water

to percolate through the soil before returning to the waterway.

Good example showing:

 Concreted river bank

 Timber boards to prevent river bed

erosion