I'm now in the technical design stage of my water harvesting/irrigation and biological cleaning systems, these will coincide with setting up an off town water system.

The dams and associated earthworks will consist of 2 dams (plus a few 'ponds'), 1 as close to the top of the property possible with a decent catch. It will fill from hard runoff from a driveway (via french drains), a back flood swale and overflow from the house water harvesting tanks. This dam will serve as an errosion control feature, a habitat and minor aquaculture pond, micro climate provision and sediment trap/biological cleaning for the second and main dam. It also will play a significant role in a gravity fed irrigation system supplied from the dams to a header tank but more on that in a minute!

The spill way from the top dam will run to the main dam via either another swale, drain or biological filtration system or possibly pipework (depending on the results of a proper survey as to levels).

The main dam will total around a 1/4 to a 3rd of a megaliter and be situated directly below the house in the center of the property. This location provides both an aesthetic feature as well as being the site with the almost the most potential for harvesting...... The site with the most potential doesn't really fit well into the larger design and the compromise is minimal.

This dam will also be the main aquaculture pond, a swimming hole, major provider of microclimates and moisture zones and the provider of a great deal of water for the gravity fed irrigation in the food forest areas.

The catchment for this dam will be made up of 3 sources, the spill from the 1st dam, runoff from the properties from above and the main house itself via the gutters.

Now to the gravity irrigation stuff!

A solar pump will be utilised to move water from the top dam to a header tank at the very top of the property, this will be used for the zone 1 growing areas. Overfow from the header will run back down to the top pond via biological cleaning processes.

Water from the main dam will be pumped to the top of the property on the other side directly above the main food forest, into ponds that act as habitat for bene's near the FF and vegetable systems (these ponds will also collect runoff fro the property above). They will also act to charge the aquifer above the FF by filling a swale with a level spillway at the very far side of the property. These ponds are the main biological cleaning system for the main dam and water will be directed back to the dam via the pillway at the end of the swale, then a trench system running to a second lower 'drale' half drain, half swale witha very small drop over it's legnth. This drale runs through the top of a planned temperate rainforest food garden and will provide moisture and humidity. before being directed back into the main dam.

The spillway from the main dam is recollected in a drain running at a very slight angle the width of the property just where the land goes alomost completly flat and turns to scrubby regrowth bush which floods often.

This drain will aid the slight drying out of this area and I will begin to accelerate succession in this woodland using the existing paperbark to nurse up acacia sp. and timber trees. Molynoxylon is a natural successor to the paperbark anyway and is already showing throughout this area so I will minimally manage these trees and add to their numbers.

The final woodlot will contain coppicing fuel wood, mid term timbers and a few select longer term timber trees in the center.

The water directed around the woodland will be caught 1 more time at the lowest point of the block as security for drought from where it could be pumped back up the block, water for fire management and as a deliberate attempt to maintain a high moisture level in the regrowth scrub outside of my boudry as a secondary insurance against fire. 

Obviously there is an extensive planting plan that goes hand in hand with this water scheme but that is a completely different update!

Although the above system sounds very complex it really only has 2 active parts, the solar pumps, these could be easily replaced with other technologies.

The system would also function with a slight drop in productivity without any pumping at all and would still supply water to most parts of the site. The only part that would not be available is the header tank for gravity irrigation and this is backed up with water tanks in various locations anyway.

anyway that took a lot of typing and hopefully is'nt too confusing!

I'll post a copy of the water overlay for the property when I finish it!