Water harvesting strategies

[Ludi]

Thank you Pak and eco for the suggestions, they are helpful.

[hardworkinghippy]

We used an altitude map to plan our house building. The house is in the altitude circle just south of the very top of the hill, hidden in a little wood for protection from the west wind. I thought it would be fun to have all of the zone one things inside another circle and build the house in the Vesica Pisces - the basic motif of the tree of life and a very auspicious spot.



We then used Google earth to plan the water strategy :



I have a lot of photographs of the different methods we've used (Water harvesting, swales, ponds, French drains, Hugelkultur, composts toilets etc.) showing how they tie in with the overall plan but the text is almost all in French. I can translate them and put them into a set in Flickr if anyone is interested.

Here's an example of the swale which can be seen in blue on the top left of the second photo :







Irene

[Pakanohida]

tres bien!

[Ludi]

Here's another map showing the entire property with contour lines. Seasonal water features are blue. Gardens are green. Small brown lines are existing berms to control runoff:

[ecodharmamark]

G'day Ludi

Great map! Now we have a much better 'picture' of where your zone 1 is located within the broader catchment/watershed. From the map (assuming that it is orientated to the north?), it would appear that your zone 1 (dwelling, etc.) is located within a valley (or perhaps on a 'saddle'?) at the lowest point (?) between two 1350' contour intervals, and between an ephemeral ('seasonal') water course to the west, and a 'water feature' (natural depression) to the east. Is this correct? If so, could you now show (on the same map) the extent of the flooding when it occurs in relation to your zone 1?

Cheerio, Mark.

[Ludi]

The serious (2 feet deep) flooding occurs in the lowest area roughly outlined in yellow, with runoff around the homestead indicated by yellow arrows:

[eco4560]

Is all the land in that map yours to do with as you wish? I can picture a large swale running through the long thin seasonal water collection area, connecting to a dam where the circular seasonal water area is at the top of the page. You can then spill the dam over into the creek (I'm guessing that's what the blue line through the trees is?) That should shift a lot of the run off away from the house area.

(Be warned my advice is based on looking at pictures in books and on the internet - not driving dozers and building dams!)

[ecodharmamark]

Excellent map, Ludi. Now we are getting somewhere.

Something like this, eco

Screen shot 2012-05-18 at 1.08.15 PM.jpg

Intercept floodwater in swale A.

Divert to primary dams B & C (the latter being slightly lower).

Any excess from C drains via D to secondary dam E.

Any excess from E finds its way back into the natural water course.

Play around with it, Ludi. It's great fun!

Cheerio, Markos.

[Ludi]

Thank you for these suggestions! The main problem we have with controlling water in the creek area (blue lines) is the volume and force of the water in flood. It is tremendous. Fortunately these events are few (every three to five years). But they make me hesitant to put a dam down there in Markos' site E, though we have considered it. The water is so forceful during flood that a few hundred feet downstream it stripped the pavement from the road. But these suggestions are definitely giving me some new ideas. I'm thinking we might put some kind of structure across the area where the upper creek enters the property to direct the water into a basin (pink). That basin could also accept overflow from the old quarry (narrow blue shape).



We hoped the round basin at the Northeast corner of the property would intercept more of the runoff, but most of it is actually to the west from where it crosses the neighbor's field. Unfortunately where the creek enters the ground is mostly rock, so we can't easily dig a swale. I'm not sure what kind of structure we could use without being able to dig. This is the situation throughout most of the creek area, where the soil has eroded away to rock. I can take photos if that would be helpful.

[eco4560]

Oooo Purple now! how exciting! Yes Markos that was sort of what I had in mind.
Do you have access to lots of rock? You could build gabions (aka leaky weirs) across the creek. That would slow the water down.
The cheating, temporary cheap solution for one season would be a line of hay bales placed on counter and spikes run through them to hold them in place. Water hits the back, is slowed down, drops out sediment and builds up behind it making a sort of berm. Might buy you some time while you get cashed up to hire an excavator....