You were right to put garbage disposals at the end; in the typical household, you should do ten other things to save lots more water than worrying about your disposer.  Studies show typical household use attributed to a disposer is @ 1 gallon day, if it can be measured at all.... so fix leaks, take shorter showers, launder less, etc.
Also worth noting:  food waste averages 70% water, so grinding and flushing it through a disposer releases that water back into the system vs. hauling it around in trucks from curbside to landfills.

While the garbage disposal may not make up a large portion of household water use, putting food waste into the sewage system increases the load of pollutants the STP has to deal with, and to my way of thinking is a great misuse of a precious resource.

Composting, worm farming, etc is much better than either using your garbage disposal unit or sending it to landfill.

Texas is flooded,  Atlanta is dry.  I think Mother Earth has decided that we are a mistake,  is trying to get rid of us.

If you need to let the water run to get hot water--
--put a bucket or pitcher under the faucet. Turn off water once its hot. Remove bucket of colder water.
Do whatever you're going to do with the running hot water.
Put the water you saved on your plants, or flush a toilet with it, or boil it to make tea. Or put it in
your automatic coffee maker and make coffee.
Or whatever.

You will usually have about a gallon of water to do something else with and that you just saved.  You could even drink it !

Unfortunately, for every water conservation saint, there is a water wasteful devil that tips the balance the other way.  In other words, you can't conserve your way out of a drought.

Don't misunderstand me, regulations stopping watering of the lawn and greenery, halting large industrial users, and other gigantic usages and users will make a big dent, but the individual has very little impact.

If the individual wants to make a big impact, they should become politically active and lobby for higher government spending on water projects.  Yeah, i

On the other hand, individual conservation may is beneficial psychologically for giving individuals a sense of control, and it is definately aesthetically displeasing to see someone wasting some scarce resource, but don't confuse ugly with destructive.

In Europe people on average use about a third of the water in the US without missing the other 2 thirds and basically living the same lifestyle. Also in this respect America is the land of opportunities... to cut down drastically without dramatically changing one's lifestyle should be possible (the same goes for energy).

Thinking globally, one of the most effective ways to both conserve water and reduce water pollution is to reduce or eliminate animal products from your diet. This may not effect your local water supply but will effect water supply else where in the country and world.

Annually in the United States, farm animals produce 1.4 billion tons of feces and urine, and much of this waste--millions of gallons--eventually finds its way into neighboring waterways, devastating the environment and wildlife.  It takes much more water, as well as land and fossil fuels, to produce a pound of animal protein than vegetable and soy protein.

 food scraps are not a "pollutant" to wastewater treatment plants, they are a resource; most sludge in the U.S. is now processed into fertilizer products, a millennium-old means of returning human/food waste to land; in NYC, effectively 100% is beneficially reused, most meeting EPA Class A standards...the richer the organic mix, the better the biosolids...
 solids actually help wastewater treatment plants operate efficiently, and many are good at efficient energy capture (esp when compared to landfills)...
 if you backyard or worm compost, that's great; but in dense urban areas municipal systems cause that to happen, and human waste/food scraps not really any different, after all...