Am I obligated to pay the rent for the period in which I could not use the enclosed yard due to the owner's arrears to the port?

The lessor must enable the lessee to benefit from the leased property by delivering it until the end of the rental period. Otherwise, the lessor is not entitled to the rent, and the lessee has the right to terminate the contract. Therefore, the questioner is not obligated to pay the rent for the period during which he was prevented from benefiting from the leased property.