We at the Water Portal, came up with some questions to ask the builder when you are buying an apartment. The more educated you are regarding the way the apartment is handling water, the better decision you are likely to make and one that will benefit you immensely in the long term. The builder does not have a natural incentive to think about wise water management as most of us don't consider this seriously when buying an apartment. If we demand better water management from the builders, they will automatically respond. . So here are the talking points. This is only a start, and we welcome more input from others to make this a comprehensive resource that people can use:
About planning for the water supply: What is the builders' estimate how much water the building likely to consume daily ? What has been the basis for calculation of different water requirement? Where is the water supply for the building going to come from ? What is the realistic picture for the availability of water from different sources that they are planning for ? What is the backup in case the planned option runs into difficulties ? If municipal water supply, what has been the trend of supply in that area ? If water tankers, where is the tanker supplier getting the water from ? Is the supply likely to be viable in the longer term ? What about potability of water source, have they tested the water quality ?
About using Groundwater 2.) If they are depending on groundwater for some or all of the supply, what is the long term sustainability ? Are there many apartment complexes and offices in the vicinity (or likely to come up soon) in which case the demand on the groundwater will be high and groundwater will deplete quickly ? What is the depth to which they went to hit water in the borewell, compare it to other wells in the locality. Is there a strategy to recharge the groundwater ?
About Rainwater harvesting
3.) Is the builder implementing rainwater harvesting ? Rainwater harvesting, either for direct use or groundwater recharge is going to be an extremely useful source of water as the shortages increase. There is no reason why builders cannot implement RWH other than that people do not insist on it. The more people put pressure, the more likely builders will act on this. Have they even heard of rainwater harvesting and the benefits? If they are using RWH, ask how the cleanliness of the roof (typically where the water is harvested from) will be ensured. Is there a different tank for RWH water and other water supply. How have they calculated the tank size ? If the RWH water is being used for bathroom purposes or (with proper precautions) for drinking purposes, it will have a real impact on the water requirement for the complex. This will need a separate pipeline system for bathroom and kitchen. Has this been implemented ?
About Wastewater Treatment 
4.) Is the wastewater being connected to the city sewage lines ? If not, how is it being handled ? There are strong arguments for implementing a wastewater treatment plant in-house for larger apartment complexes. Not only does it create a source of water for use in landscaping or carwashing, it also reduces pollution of groundwater and reduces strain on the city infrastructure. Again, have they heard of this possibility? If they are treating wastewater, how are they planning to use or dispose of the treated water. If electricity supply in your area is erratic, does the treatment plant design take that into account ? What will be the process and cost for maintaining the treatment plant ?
Landscaping
5.) Is there a lot of grass and shrubs being planned ? Trees take up less water (and local varieties rather than exotic varieties) are a better option. What are the current plans of watering the green area - the kind of water and the kind of system.
Incentivizing water conservation: 6.) The cost of procuring the water for use in the apartment complex is likely to be quite high or is likely to increase rather than decrease. So people need to pay for the water they use rather than paying a fixed amount per apartment. This automatically incentivizes people to conserve water. But when there is no way to measure how much water you are using, there is no way to set up a system that rewards people for using less water. Therefore individual water meters are essential for each apartment ? Are these being installed ?
Water-Saving Devices: 7.) Have the builders installed water-saving devices ? These include low-flow showers, dual flush toilets with smaller tank size, and low-flow tanks.
Other points to think about: 8.) Solid waste management: Is there is a system to segregate garbage into organic and non-organic ? Kitchen waste can be composted locally to provide fertilizer for the garden. Has at least a space been earmarked so that the residents may put a system in place. 
9) Once the Apartment Owner's Association is in place, it would be good to monitor the water use closely and bill people based on usage. So the water bill for the apartments should be calculated by usage rather than clubbed into the maintenance. Leakages would also need to be monitored. Water loss through leakages and ineffective plumbing is rather large in most housing complexes. 10.) There are several 'green building' technologies that are becoming mainstream. These include solar heaters, designing to maximise the use of natural lighting, and to reduce energy requirements for heating or cooling. These kind of technologies will pay off in the long run and need to be incorporated early, as retrofitting will be difficult and more expensive. Builders will start thinking along these lines only if buyers demand these.