At this point the discussion thread has just started.
https://www.backyardchickens.com/t/869559/water-management-and-strategies-for-water-conservation

The following are links to articles about water management and or sources for supplies and even whole systems.

Water Use caluclator for your home.
http://www.glendalewaterandpower.com/save_money/water_calculator.aspx

a monitoring system for water cachement systems
http://www.biolytix.com/how-it-works/

an innovative Septic system may or may not be for US use.... I am looking into that
http://getwatergenie.com/

discussons on Greywater use I havent read it yet
http://greywateraction.org/content/about-greywater-reuse/

Though alot of us use what we can for water storate I think these are pretty cool looking
http://waterwalltanks.com/

water filtration in the UK
http://www.pozzani.co.uk/index.php?menu=1

Links for Gabion dams
In this page there is a time series with a video showing a flash flood.
http://gabion.blogspot.ca/

Here is a permaculture video on gabions...
http://www.ecofilms.com.au/reversing-desertification-with-gabions/

This page explains a little better why they work:
http://www.santafebotanicalgarden.org/visit-us/museum-hill-garden/historic-gabion-dam/

A method of harvesting water from fog. I know there are arid places that do get fog. San Diego coastal is one of those.
These are stunningly beautiful I have to say
http://urbantimes.co/2014/04/towers-harvesting-water/

Article on how Goldfish handle very cold temps.... I use goldfish for mosquito management in my animal water tanks.
Gold fish Article

Addressing smell in wells or cisterns
Hydrogen Sulphide or Rotten egg smell in water

Reducing Algae bloom in ponds
http://ohioline.osu.edu/a-fact/0012.html

arizona article
http://www.american-oasis.com/chapters/0

Source for test kits
www.hach.com/testkitsguide

industry source for water and waste water management...
http://usabluebook.com/