Benefits Of Rainwater Harvesting In Rim Country


Water is essential for life and, in the town of Payson, essential for growth.

For this very reason, water is a hot topic right now in Payson, and that affords me the opportunity to write a series of water-focused articles. I'll try to address the issues most important to the residents of Payson and the surrounding communities.


Jim Ryan

But first, this week, besides introducing this series, I want to focus on a few of the objections and concerns that arose during my initial conversations about rainwater harvesting (RWH) with residents and civic leaders in Payson. Let's call this week's segment, "Water Stories -- Myths and Misconceptions."

Me: "Have you considered sustainable water supply alternatives such as rainwater harvesting?"


1) "We already have enough stagnant water around here."

2) "We have Dengue here already. We can't risk increasing the mosquito population."

3) "If the rain is collected by individuals, there won't be as much run-off. This run-off is essential to recharge our aquifer. The aquifer will suffer if we rain harvest."

4) "People who RWH will tend to plant excess or inappropriate vegetation. When that extra vegetation needs water, they'll likely use municipal water to maintain the plants."

5) "The rainwater belongs to Salt River Project (SRP)."

6) "There isn't enough rain here to justify RWH investments."

Now for some myth busting:

1 and 2) RWH does not create stagnant water or breeding grounds for mosquito populations. In fact, just the opposite is true -- a properly designed and implemented RWH system greatly reduces the standing water. RWH systems capture the rainwater that falls on roofs and filters it, then safely and securely stores the water for later use, away from the reach of insects, including mosquitoes.

3) The town's investigations indicate that at best, only about 16 percent of rain that falls in the area ever makes it into the ground far enough to eventually recharge the local aquifer. Most of the rainwater in Payson now becomes run-off, which feeds a river that ultimately helps support growth in the Phoenix area.

According to National Geographic magazine, "520 million cubic yards of groundwater is being removed from aquifers annually in Arizona; about double the amount being replaced by recharge from rainfall."

Meanwhile, Payson has significantly increased its extraction of groundwater, and is approaching its "safe yield" limit for its aquifers. Clearly the best way to relieve "pressure" upon the local aquifers is for the town and exempt well owners to stop pulling so much water from them, and RWH offers an ideal means to displace some of those current excessive demands.

It is simple logic to comprehend that capturing and using 90 percent or more of the rain that falls on your roof is much better for the aquifer than hoping that 16 percent of that rain eventually finds its way into the local aquifer. Besides, all the rain falling on the ground, or on surfaces other than on roof collection surfaces, is still available for infiltration (or run-off).

4) There is always the possibility that some people will "cheat," but that same possibility exists today. Besides, these people will be subject to the same water restrictions and penalties that exist today, and which will certainly be in effect even if RWH is widely adopted.

If instead of promoting RWH for irrigation purposes, the town introduces incentives or ordinances, which steer new construction toward dual supply systems, and the 300 to 400 current, exempt well owners (within corporate limits) toward complete RWH potable systems, this issue essentially disappears.

5) Rainwater that falls on your roof does not belong to SRP. They acknowledge that they have no more claim to that rainwater than they do to the bottled water you buy and store in your refrigerator.

6) Now, finally, to the question of whether there is enough rain. The town's Web site (water department section) reports "Precipitation in Payson has historically averaged 22 inches per year. However, during periods of drought, the average amount of precipitation is 17 inches or less." These figures are supported by a variety of meteorological stations.

For illustrative purposes, let's assume the average 22 inches of rain per year falls on a 1,600 square foot roof. That rainfall will yield more than 20,000 gallons of usable water per annum (or 15,600 gallons in a drought year of 17 inches rainfall). Dividing that 20,000 gallons by the average Payson usage of 86 gallons per day, yields 233 days of water use for one person, or 116 days for a couple, or 60 days for a family of four. Ample for the "seasonal" resident, but not sufficient for the permanent resident, unless we add some additional roof collection surfaces, or, instead, use rainwater to supplement traditional municipal supplies and therefore relieve demands upon the aquifer. If widely adopted, this strategy could mitigate the need for spending $30 million to tap the Blue Ridge Reservoir, or more likely, fill the gap during the eight-plus years before this project will be completed.

So, returning to the issue of how we use the rainwater, if we consider utilizing rainwater for even a small portion of the typical Payson area newly constructed home's use, say even for flushing toilets, we will have effectively and permanently relieved the aquifer of a significant demand.

Toilets and laundry are the two largest consumers of water and both could be served primarily by rainwater if new homes were designed and built accordingly.

Meanwhile, opportunities for the town to lead by example should not be overlooked. Specifically, any new public construction, whether it is the new fire department building or the proposed covered rodeo grounds, should be carefully evaluated as demonstration projects for RWH. These highly visible community assets could each serve to demonstrate the technology's applicability and to educate the public that RWH can be a safe (no mosquitoes) and sustainable alternative to increasing demands for groundwater.

Until next time, remember, we all drink rainwater, some people just prefer to do so before it hits the ground.

Whether for home or horses, rainwater is the ideal sustainable and naturally soft water supply. Water tanks can be plastic (polyethylene), galvanized steel, concrete or fiberglass depending upon the application, location and budget.

Jim Ryan is the president of Agua Solutions International, which designs, specifies and installs Rain Water Harvesting and water purification systems for residential, commercial and industrial applications. For more information, call (480) 703 1500 or at

Commenting has been disabled for this item.