So I would encourage you to consider if they are poisonous snakes or not... if not, they are probably quite beneficial. Snakes eat rodents, so they may be eating mice, gophers etc. which is great. First off, I'd say to rid the area of the food source, ie: rodents, would help... there are also decoys like this one that is supposed to help.
There are many natural snake repellent ideas that allow you to get rid of snakes without harming them.
If you have snakes, you have a food supply for them, i.e. rats and mice. Here are some things you can try.
You might want to consider snake fencing.
Be careful with purchased or home remedies if you have children or pets, most are too toxic for them. I deal with rattle snakes just about every day. If poisonous, tread lightly and call in the pros or animal control to remove for you.
We have a lot of rattlesnakes where we are. We have snake fencing, and can you believe they climb right over it (24" high) and end up in the back yard. We don't have rodents, or any other food source for them. They just have their territory, which they go over looking for food. I wish there were a simple sure way to keep them away, but we are in their territory just as humans have taken over most other animals territories, so where are they to go?????