My theory is if the water pipes coming in from the meter are as old as the house, they are rusted inside (they often were made of cast iron) to the point that only a pencil-width space is allowing water to reach the house. That would be the low water pressure cause. It's up to the landlord to spend the money to dig up the yard to replace the pipes, and that costs a lot of money.

We are having the same issue and our house is less than 7 years old. I am thinking it may have something to do with our water softener or the water pressure regulator. We had the anode rods changed in our two water heaters back in June. Your landlord should have a good reliable plumber come in and assess the situation.