Every HOA is different and so are their covenants, conditions and restrictions. Some HOA regulations require homeowners to keep foliage alive and the color of the lawn to stay green through sufficient watering.
According to Virginia Tech's A Landscaping Guide for Homeowners Associations (http://www.manassascity.org/DocumentCenter/View/3981):
Most plants need about one inch of water on a weekly basis. Normally, cool season grasses go dormant in the summer and only need water in cases of extreme drought.
Most of the time spent on lawn maintenance is spent mowing. Mowing correctly is one of the easiest things that can be done to help keep turf happy. Because mowing causes physical injury to grass, it is important that no more than 1/3rd of the total leaf height is cut at any one time. This allows the grass sufficient leaf area to photosynthesize the energy it needs to heal. When grass is very high due to wet weather, it needs to be cut in stages, taking 1/3rd off at a time and waiting until the clippings left on the ground disappear between cuttings.
We suggest the following tips and tricks in order to maintain a healthy, intact lawn during the extreme heat of the summer. http://yardcare.toro.com/maintain/how-to-maintain-the-grass-in-extreme-heat/