Dams and trees - water conservation

[Peter W]

Hi everyone,
After some months of asking theoretical questions from Hong Kong, I am now living with my wife on our 14 acre block in Nimbin. I have done the PDC course at the Permaculture Research Institute at the Channon - I learned heaps and have been applying my learnings in the production of my first 18 day compost heap and developing a 10m x 6m vegie plot. After surrounding the plot with a buried bandicoot barrier (immense labour) and a mesh fence, and establishing a first no-dig bed in the plot area, we planted our first lot of seedlings yesterday.

By the way, welcome back Darren from PermacultureBiz - I was wondering where you had got to and missing your informative contributions.

To the question about water and trees: We have a dam not far from the house, fed mostly by a spring which sends water from the top of the block via a tree lined gully. The dam is surrounded by trees - sally wattles, camphor laurel and others. The 'pool in the forest' effect created by the trees is very attractive, BUT ... A local visitor the other day said that the trees around the dam would be taking an enormous amount of water and preventing the dam from getting filled up properly; he said we would be losing more water to the trees than to evaporation, and that we should cut down the trees.

The idea of cutting down trees goes against our current thinking: we are planning to plant lots of trees and to develop a rain forest canopy on the top part of the block and control the weeds and grass.

What to people think about this?

Peter

[JackieG]

Hi Peter
I am far from an expert (just opinionated!!) but to me it always seems terrible to cut a healthy tree, if the dam will meet your needs with the trees there, then theres not much of a problem, perhaps if this is not the case, a balance maybe struck for you, the trees and any animals that use the trees aswell.

Good Luck with your new adventure!
Jackie

[Chook Nut]

Hi Peter,

Exciting to hear its all going ahead for you now Sounds like that vegie patch is a fortress!

Can't give you any advice but i thought i would ask you about the Camphor Laurels. I have a few on my acerage and have been told i should get rid of them as they are considered a pest/weed plant. I will have to check with my council on that one before i get out my axe! I am quite happy to lose them if this is the case. So i would say just check whether they are a pest in your area, that way you dont have to feel bad about chopping them down!

[permaculture.biz]

Hi Peter,

Thanks for the thoughts - things have been very busy with no sign of abating.

My rule of thumb is to maintain trees and shrubs around the water's edge with the exception of the dam embankment (wall) as they would undermine bank's structural integrity (shallow/spreading root shrub-grasses ok though). Your friend is right - the tree's will use some water - however they will also shade the storage and therefore cool its water - the cooler the water the less evaporation - in addition most water loss thru evaporation is not thru the sun but from wind - particularly hot winds - so any shelter is a good thing.

cheers

dd