About 40 percent of rivers, lakes, and estuaries in the United States are not clean enough to meet basic uses, such as fishing or swimming. You might think it’s caused by easily identified polluters such as industry, but the greatest source of water quality problems is non-point source pollution.
Birmingham and other urban areas are major contributors to NPS pollution. That is a result of storm water runoff from paved surfaces and rooftops as well as the relatively high concentration of chemicals, waste materials, fertilizers and other potential pollutants associated with lawn and garden activities.
Think about what happens when rain hits your roof and flows away. Water flowing across lawns, streets and parking lots picks up dirt, trash, fertilizer, lawn chemicals, soil, grease, bits of rubber tires, animal waste, and other things left behind by people and animals.
Traditional storm water management practices focus on the collection and rapid removal of rainwater from the point of impact through a system of underground pipes and storm sewers, transferring water directly to sewer outfalls without pre-treatment. The goal is to reduce or control localized flooding. But it generates polluted runoff, disrupts the natural hydrologic cycle, and adds to the contamination and scouring of streams and rivers.
In contrast, a “water smart” plan would treat water as a resource to be preserved, maintained, and saved for a “not so” rainy day in the future. This new approach seeks to manage storm water on individual home sites in a decentralized manner as opposed to the traditional centralized approach.
Homeowners can do several things to chip away at this monumental problem. As with most large problems, a number of small efforts can have a large cumulative effect on the problem. This is true with rainwater harvesting. It is an ancient practice enjoying a revival as an alternative water supply with the added benefit of reducing storm water runoff. Communities in ancient Rome were designed with individual cisterns and paved courtyards, which captured rainwater to augment supply from the city’s aqueducts. The practice involves collecting rainwater from a roof or other surface before it reaches the ground and storing it for future use.
This summer in the Birmingham metro area three rainwater harvesting workshops were conducted with more than 120 homeowners participating. The workshops’ objectives were to inform and train homeowners about basic storm water issues and how harvesting rainwater could save money and improve water quality by:
- Keeping relatively clean water out of the combined sewer system and make it available for non-potable uses.
- Reduce the energy and chemicals needed to treat and transport storm water.
- Reduce the volume and peak flows of storm water entering the sewer, reducing flooding and combined sewer overflows.
- Reduce the volume of potable water used for non-potable applications such as irrigation and toilet flushing.
After the workshop, 84 percent of the participants said they were very or extremely likely to install a rain barrel or rain tank to harvest water from their homes’ roofs. A similar amount said they planned to store the water for use on their landscape or vegetable garden as a replacement for municipal water use. In addition to reducing runoff, homeowners would reduce their need for municipal potable water for uses not requiring potable water.
The survey took a snapshot of the participant’s level of understanding on eleven major areas. We rated understanding on a scale from 1 to 5, and the average pre workshop score was 2.8 while the average post workshop score was 4.4 or a 57 percent increase in their level of understanding. Some of the topics covered included how to compute potential water harvest from a roof top, how to build your own rain barrel or cistern, safety concerns, system maintenance and potential uses for the water.
Four months after the workshop, a follow up survey was conducted to determine what the participants had done and what they planned to do in the future. One hundred surveys were sent out, and we received 40 responses. Forty percent had already installed a rain harvest device; 32 percent were still researching but planned to install a device in the future; and another 20 percent had the system designed but not installed. We asked participants who had not installed rain harvest devices why they had not, and the two greatest reasons were the rainy summer (35 percent) or a lack of time (20 percent). However when asked if they planned to install a system before the summer of 2010, the response was 95 percent positive. Several who had not yet installed a system said things like, “It has been so wet I did not see the need of installing a system until next year” or “I understand how to and I still plan to install the system later”.
We asked those who did install a system what they were using the water for and 55 percent said irrigation. This number was lower than anticipated based on the workshop survey but can be explained by the unusually wet summer and fall in the Birmingham area. Other uses included washing cars (7 percent), cleaning sidewalks or driveways (7 percent) and a small percentage using water for houseplants and pets.
Rainwater harvesting is one small part of the solution for NPS pollution in urban areas, but the potential impact is significant. The trend of rising water and sewer rates in the Birmingham area has and will continue to cause interest in rain water harvesting from an economic standpoint. Also, from an environmental concern, we expect interest to continue as well. In addition to rain water harvesting, a full 80 percent of the respondents expressed an interest in attending other water management workshops such as designing a home rain garden to divert storm water from the storm drain system. This response indicates a desire to have an impact on the overall water quality and to reduce storm water runoff through methods other than potentially money saving methods such as rainwater harvesting. We are now planning rain garden workshops for 2010 to meet this expressed need.
A success Story for ETP20R: Rainwater Collection, Water Conservation and Irrigation Methods Training – U&NNTP
By Tony A. Glover from Cullman County on 2009-12-10
Co-authors: Sallie M. Lee, Charles B. Pinkston, Catherine Sabota, Kerry P. Smith