Mole hills in gravel would be harder to deal with.There are various things you can try. There's an ultrasonic deterrent you sink into the ground that is said to deter them but I couldn't get it down deeply enough in ours. As your lawn was recently rotavated this shouldn't be a problem. They don't like vibrations -I have tried stamping about over the tunnel and it seemed to work - the mole would still be there but might be persuaded to move off the lawn. We had one that worked its way all along the front of a flower bed! Yours looks as if its heading in that direction too.
Some people try sticking childrens windmills over the tunnels for the same effect.

You can buy traps too. Look up mole deterrents on Google for several other suggestions.

The deep dips don't show up on the photo but you can brush the soil heaps back into the dips and the grass will grow through.

Maybe castor bean extract would help?

Crumbs Tug,isn't that ricin?

What an image! Like an horrible combination of terrorism and "Caddy Shack"!
Not the extract that I was thinking of--more like cheap castor oil! Burrowing animals don't like the taste, and shove off. It's sold as a mole and gopher repellent here in the U.S.

Thank you for all your help, very much appreciated. Pest control remove the moles at 50.00 a visit, but after damage has been done. I will now buy all those items suggested, including kids windmills! Thank you all.

Lol, Tug. I never heard of anybody who liked the taste of that... that's very useful to know - never seen it mentioned before. Do you just pour some into the tunnel?