notes from a correspondance in response to thoughts on water diversion and distribution systems.  optimally using the KSOP for layout planning of the site features.

I'm in favor of the 'leaky' canal (aka diversion drain/irrigation spreader drain) made from native earth for both collection and distribution of water.  vary the slope of these in relation to your soil texture and general landscape shape and slope to get the desired delivery. the plastic flag  with chain or bar is a small piece, cheap, highly mobile, and easily fabricated. 

Plastic HDPE pipe as distribution is also an awesome option.  diameters vary based on needs.  3/4", 1", 1.5", 2", ...  All of these diameters are relatively affordable and highly mobile.  if water is very valuable/cost are high then the expense of pipes is great to compare with earthwork costs for drains and water lost in transit. options work for a variety of pressures (1 PSI = ~6.9 KPa)
some suppliers in Australia and USA: looks to be ~$1-4 per meter depending on diameter plus couplings, etc.
http://www.polypipe.com.au/category2_1.htm
http://keithspecialty.com/water.line.pe.htm
http://horsleywholesale.com.au/catalog/Poly_Pipe_Rural_Fat_Stripe_PPI-133-1.html
http://www.powerflexfenceonline.com/product_p/hdpe1-1-fslash-2.htm
http://www.flyingwplastics.com/pdf/polyethylene-water-tubing-2007-5.pdf

for irrigation, k-line sprinklers can be useful and are also highly mobile.  http://www.k-linena.com/new_page_2.htm

also found this file on large diameter flexible polypipe from Texas A&M
http://gfipps.tamu.edu/PRT-Support/PolyPipe/Using%20Flixble%20Pipe%20%28Pub%20L-5469%29.pdf

large diameter supplier
http://strohirrigation.com/products