Ardunio type, water sensor, actuator, automation

Water Sensors, alert, Actuator automation. Hi, This project is for my Flood irrigation farm. Background is that we have water supply channels that take water to an irrigation bay. We manually open the irrigation bay outlet to let the water flow down the bay/paddock/field as the water floods down the bay it wets the soil giving the pasture water. When the water reaches 75% down the paddock we then go and shut that outlet and open the next outlet. For more information see here [login to view URL] and read the Bay/border strip irrigation section. 1st stage - URGENT Mobile sensors that detect the presence of water in the bay and then let me know preferably via my android phone that the water has reached that point. Their will be at least 6 of these in operation at one time. So I need to know which sensor has been activated. This could be via a GPS being attached to sensor that when water being detected the alert shows up on a google sat image or something. However being able to simply individually label/identify the sensor on my phone maybe be easier. Once I know the water has reached that point in the field/bay I then can go and manually change over the water outlet to the next bay/field/paddock. I will then move the sensor to that new bay. 2nd stage This is a extension of the first stage. Each sensor can be “paired” with a 12 volt actuator such as here [login to view URL] So once the water reaches the sensor it tells the 12 volt actuator located at the water outlet to close and the next 12 volt actuator to open. Then the sensor in the next bay does the same thing. There by automating the irrigation process. The hardware I suggest using is [login to view URL] (synapse wireless SNAP mesh microcontroller) or other products in the synapse family available from solarbotics. Or alternatively XBEE could be used. However I’d be keen to keep costs down by using the onboard microcontroller of the SNAP products to control relay cards for the 12v actuators. Also good outdoor range is required of the wireless modules. Arduino products. Relay cards to interface between microcontrollers and 12v actuator Gateway from mesh network to my android phone. Their is an adsl internet connection available for this if required. I would assemble the hardware here, I need the freelancer to tell me which hardware he wants me to use and provide the programming and how to assemble and configure the hardware. I would expect to freelancer to understand whats required and provide initiative and input on how to better achieve the projects outcomes. For example the full automation stage will require thought and useability as there are over 200 automated outlets and perhaps some check sensors and status feed back will be required to make sure actuators actually open and close etc. thanks for your time.