Conversely you can go DOWN to the Permit Resource Management Division (see above link and get adress, map, telephone numbers) and look up the address. If they having nothing on record then this is a wild-cat contractor doing everything without permits. If he is on record and you see "permit" activity then call down there and see if you can speak to the inspector in charge of road permits/design. Tell THEM of your problem and they most likely will get out their quickly and put a stop to this plus look for recourse from not only the contractor but the OWNER OF THE PROPERTY!!
Also, contact the OWNER of RECORD on the subject property via registered letter and tell them you are contacting an attorney unless this matter is resolved immediately!! You could even call in the environmental folks from the county and get them involved also!! Water erosion, especially when it may intrude to other sensitive environmental areas, is NOT being tolerated. I'd also get a pit-bull dog of a lawyer and filed a lawsuit threatening a cease and desist order on the property!!
It seems as if he has substantially altered the natural flow of water. Potentially leaving homes in a landlocked position is a very serious issue, obviously. On the other hand, if he truly is broke, your relief might be difficult to obtain in a timely manner.
Contacting the media as Lynn has said, may not be a bad idea. If you would like referrals to real estate attorneys or any other resources, please feel free to contact me and good luck.
Also contact your local district rep. who is elected offical. Have you considered contacting media.