permaculture

[sinergyinaction@netscape.net]

Hi,
I am trying to figure out the amount of water (either from surface runoff, an 
existing irrigation channel, a spring, and a couple of existing wells) I need 
to store in order to face summer water shortages and/or drought periods.
 
The main purpose for storing the water is that we are setting up a tree crop 
system from scratch, mainly fast growing nitrogen fixers (quite densely 
planted), like casuarinas and/or acacias to improve soil structure (2m deep 
clay layer), by creating a lot of biomass.
These trees would also be interplanted with cover crops, such as alfa-alfa or 
other cover crops suited to the area and season (mediterranean southern 
Spain) to increase even more the amount of biomass available. 
There seem to be a lot of water around from my description, but in drought 
periods the water from the water channel sometimes doesn't arrive (and it 
usually flows from early june till the end of august)
and I am not yet sure how much water can be pumped out of the wells.
Very much linked with the initial question is also how much water might this 
this system need for irrigation purposes, or how could I compute this? If I 
knew this I could estimate the size of the tank.
 
I assume that during the establishment fase (first three years) more water 
and more regularly will be needed that after this time.
 
One of the main worries that I have is not to design a storage system that is 
too big for the need that I have or too small, also because it would probably 
occupy a lot of useful growing space and the total surface is of about 2Ha.
Looking forward for insight
Antonio
___________________________________________________
Try the New Netscape Mail Today!
Virtually Spam-Free | More Storage | Import Your Contact List
http://mail.netscape.com