Question
HI i would like to know how many litres of water is needed to irrigate 1 acre of tomatoes live in aplace where  it hardly rains

Answer
Please provide the following information when you are able.

1. The watering requirements for the plants

2. The local evapotranspiration rate

3. The soil type and filtration rate

The above information is needed to answer your question.  I look forward to hearing back from you.