GRE Argument 'Restricting the Water Flow'

I'm preparing for the GRE analytical writing session which will happen in 5 days. My target score is 4.5. Please review my practice essay and make feedback. Thanks a lot!

Prompt

The following appeared in a letter from the owner of the Sunnyside Towers apartment complex to its manager.
"One month ago, all the showerheads in the first three buildings of the Sunnyside Towers complex were modified to restrict maximum water flow to one-third of what it used to be. Although actual readings of water usage before and after the adjustment are not yet available, the change will obviously result in a considerable savings for Sunnyside Corporation, since the corporation must pay for water each month. Except for a few complaints about low water pressure, no problems with showers have been reported since the adjustment. I predict that modifying showerheads to restrict water flow throughout all twelve buildings in the Sunnyside Towers complex will increase our profits even more dramatically."

My Essay

In the letter, the owner of the Sunnyside Towers complex introduced his plan of restricting the water flow of showerheads in all twelve buildings to one-third of the current degree. The owner argued that this will be dramatically lucrative since it will save a lot of expanses of water and only a few complaints appeared yet. However, on three specific points, his or her argument doesn't hold water.
First, the total water consumption may stay still despite the decreased water flow since the owner hasn't checked the actual readings yet. A reduced water flow will probably damage a person's shower experience. For instance, one will notice that it's harder to wash off the dirt on the body. Thus, it is possible that the residents will spend more time on the shower and cost more water. This may counteract the savings from cutting down water flow and result in unchanged water consumption.
Second, although current complaints the owner received aren't very much, their number may increase in the future. For instance, the limited number of complaints may due to the cozy weather of this time. If the temperature increase after a few months, people would spend more time taking showers and then suffer more from the reduced water flow. In that case, they will make more complaints. Some tenants may even decide to end the lease, which is extremely harmful to the owner's profits.
Moreover, restricting maximum water flow to one-third of the current degree may damage the assets of apartments. For instance, the water pipes would probably rust faster because there would be more stagnant water in them. Also, flowers in the garden might be in great danger due to the decreased water for irrigating them. Therefore, the owner couldn't assess the profits simply based on the water consumption. The changes in upkeep also matter.
In conclusion, the owner of the Sunnyside Towers complex failed to give a convincing argument. The owner couldn't assure the water consumption is reduced as a whole, the number of complaints wouldn't increase in the future, and no extra damages would occur due to the low water pressure. If any of these three weaknesses remain, his or her evidence doesn't hold water.