Can my landlord have the water supply turned off tomy house?

No, your landlord cannot legally do this.  If you are behind in your rent or otherwise in breach of your lease, your landlord must avail himself/herself of a judicial remedy (i.e. take you to court).  Alandlord cannot use "self help" tactics and shut off your water (or any utility) in order to get you to leave the premises. 

The fact is that if your landlord has done this, you can sue.  If there is no water to the premises then this is a case of what is known as "constructive eviction".  If you have to move out you may a legal claim for any costs you incur (such a hotel; extra travel time; storing belongings; etc.) and you can also get a court order allowing you to move back in (subject to a later legal eviction if you remain in breach of your tenancy).  Additionally, there is the potential for you to potentially to recover your attorney's fees.  You may also be entitled to other remedies, depending upon specific state law. 

At this point, you should consult with a tenant's rights group or an attorney specializing in landlord tenant law.  If money is an issue for you, see if you qualify for representation by Legal Aid.  If not, check to see if there is a law school nearby to where you live; they typically run free/low cost clinics that handle these type cases.  You can also contact the local Bar Association in your county; they may have a list of attorneys who will take your case "pro bono" (for free) or at least for a reduced fee based on your income/circumstances.