Whenever damages are awarded under the provisions of section 40:37-111 of this title to an owner of real estate, and benefits are assessed against the same owner, the county park commissioners may, when both the award of damages and the assessment of benefits have been finally confirmed, deduct the amount of the benefits assessed from the damages awarded, and set off the benefits against the damages by proper charges and credits, in order that only the excess of damages, if any, shall be paid, and only the excess of benefits, if any, collected.