(Written by Pat Casey – NMHBA President – Originally published in the May 2013 Housing Journal)
Water Conservation – It’s Complicated
With all the time and energy spent during the last several years fighting over the energy code, I believe we’ve lost sight of a much larger problem looming in the state that has the potential to impact building much more severely than energy. This problem is water, or lack of water.
With recent droughts and an ever-increasing population in New Mexico and the Southwest in general, we are pushing our water supplies to the limit. This year the Carlsbad Irrigation District filed suit against Artesia and Roswell to stop them from pumping ground water. The Carlsbad Irrigation District believes the pumping of groundwater upstream is affecting the amount of water in the river which is harming their senior water rights holders. This along with the pending Bounds case and the dispute with Texas over water is just a small sample of the litigation involving water.
Recently, along with Jack Milarch, Randy Crowder, Mike Buechter, and Randy Traynor, I had the opportunity to meet with Scott Verhines, the state water engineer. We wanted to take the opportunity to discuss with him what the home building industry could do to encourage water conservation. It was a very enlightening meeting. Verhines explained that some forms of water conservation may actually harm people downstream. For instance, if a town that pumps groundwater for their water supply and returns their treated water to a river or stream starts using less water, returning less water to the stream or river can negatively affect people downstream who rely on that water. When individuals harvest rain water they affect the amount of water that downstream users have to use. As it turns out, water conservation is a lot more complicated than one may think.
The biggest user of water in the state is agriculture, using about 80% of the state’s water. Public water systems, which include residential, commercial, and industrial uses, account for about 8% and domestic wells make up just under 1%. As you can see, residential use of water makes up a very small percentage of water use but if you include commercial and industrial it is almost 10%.
Over the past several years there have been some advances in conservation. Dual flush toilets are becoming more popular. Clovis requires a recirculating pump if a hot water line is more than 20’ long and many of the green building programs have requirements for water conservation. It is interesting to note however that some items we install as conservation measures do not work well on their own. For instance, low flow shower heads have limited value if you still have to wait for hot water to reach the head. A low flow shower head teamed up with a recirculating pump is very effective in reducing water consumption. The advantage to recirculating pumps is they are easily installed in older homes. The pumps install under a sink typically at the farthest point from the water heater. All of the plumbing is hooked up under the sink so it is usually not necessary to open up the wall to access the plumbing. There needs to be a power source installed under the sink if there isn’t one already available but this can usually be done with little to no damage if there is an outlet above the sink. I have installed several of these in existing homes and they work quite well. Simply turn the pump on, wait a couple of minutes, and when you turn the faucet on there will be hot water. Some even have remote controls which allow the pump to be turned on from anywhere in the house.
Another water-saving system that I prefer to use on new houses is what I call a manifold system. When the house is roughed in, every water fixture gets its own hot and cold water line run to a central location. This is usually to the mechanical room where the water heater is located. These water lines are then plumbed into a manifold for the hot water and a manifold for the cold water. Each line has its own shut off at the manifold so shutoffs at the fixtures are no longer needed. This has a couple advantages. First, every fixture can now be shut off without having to shut off water to the whole house. In colder climates the hose bibs can be shut off in the winter and tubs/showers can also be shut off. Another advantage is that it makes it very easy to operate the valves on a regular basis to keep them operating correctly. How many times have you tried to shut a valve on a fixture only to find that it hasn’t been used in so long that it cannot be shut off? With this system, once a month you can access the manifolds and in a couple of minutes cycle all the valves to keep them operating. Another advantage to this system is it allows for future changes to water sources. Someday we may use grey water to flush toilets. If we incorporate an extra water line from the outside to the mechanical room which could hooked up to grey water in the future, it would be easy to switch the toilet lines to take advantage of this. This is also a passive system. There aren’t any pumps to maintain and the system requires no energy to operate. Probably the biggest advantage to this system is the potential for water savings. Since each fixture has its own “home run” to the mechanical room, you no longer have to wait for hot water to go around the house to many fixtures before you get hot water. If the water heater is centrally located so the water line lengths are kept to a minimum, very little water is needed to get hot water. In most cases it should take less than six cups of water to get hot water.
On the other side of the equation, we should be plumbing our waste and drain lines so that in the future the grey water and black water can be separated. This requires the grey and black water lines to be separate until they reach the outside of the home.
With the uncertainty in the water supply now and in the future, I believe water issues are here to stay. While housing uses a small percentage of water, it is important that all water users do whatever is possible to ensure a reliable source of water now and in the future. We will continue to engage the state engineer so that we can be a part of the solution which is fair to our industry and which protects our most important natural resource. All of us working together will help ensure that there is an ample supply of water for future growth in the state which will keep our members working and contributing to the economic growth of our state.