Water and electricity under my name and tenants not paying

[Nina Ning]

I have a single family house with solar panel installed in California. So I have to be the one on the bill for the solar generated power. As far as water, tenants told me she signed up with the city to take over the water, but I just found out that the water is still under my name and two months of water bills are not paid. I had to pay for the power and water and send the bills (two months) to the tenant but no responses. She did pay the monthly rent though. I sent her several emails, texts but only one response saying she has a chaotic situation. I replied to her asking about the situation and  willing to work out something with her but still no response. What can I do in this situation? It's been about 2 to 3 weeks when I first contacted her. 

Thanks for your advise. Nina