Do I have the right to expect the common area landscaping to receive sufficient watering to retain green grass throughout the summer months?

Depending on what the CC&R document declares your expectation may or may not be reasonable.  You should locate and read the CC&R's which shoould be recorded in your counties recorders office.  This should explain the duties and obligations of the HOA as it relates to common area landscaping.  If you would like assistance in interpreting this document and explaining your rights, I invite you to contact me at 415-827-1425