permaculture

["Gaden@ziplip.com" <Gaden@ziplip.com>]

I see a lot of people creating ponds & dams designed like icecream scoops out 
of the ground. That is, steep sharp sides. 

As with so many ecosystems, the edges are where much of the action is 
happening. (Respect The Edges, Long Life The Edge (of Chaos)). Healthy 
pondage needs at least one, if not several, ledges. These allow growth of 
plants (and associated fauna) around the edge. This plant growth filters, 
removes (well, transforms) some of the excess nutrients, protects juvenile 
insects/fishes etc. and many other functions. On a smaller scale, potted 
waterplants can be placed in the water.

Ponds tend to act as nutrient sinks/sumps. This nutrient content has to be 
transformed and transferred. A balanced system will recycle this 
indefinately. But in many systems, input exceeds capacity. Nurification 
occurs and the system flips into anerobic mode becoming smelly, stagnant, and 
deoxygenated. Thus other means such as harvesting plants/animals from the 
system helps rebalance the system.

For example: The duck/azolla/carp/tilapa/silkworms/mulberry pondage systems 
seen in asia. Much of the nutrient flow from the households/pigs etc ends up 
in the pond. It cycles through the system and is eventually removed. Ducks & 
fish get eaten. Azolla ends up a nitrogen rich mulch. And each year or so, 
the pond may be drained and the bottom sludge spread on surrounding fields. 
Clever idea...

Gaiden