If you have lived in Arizona for any amount of time you know water is a precious commodity. Finding new and innovative ways to use all available water has never been more important. Although stormwater normally is considered a nuisance there are cities here in Arizona that are taking an innovative approach to its use for Urban sustainability. 

Mesa is one city that has begun to use techniques to divert, store and utilize stormwater runoff to support native and designed landscapes. One major advantage to this practice is normally lost water can now be utilized to supplement, and sometimes reduce the need for, traditional methods for stormwater management. They are joined by many other cities across the country that have begun to use this development plan. 

The term for this is LID or Low Impact Development. This term is used to describe a land planning and engineering design approach to manage stormwater runoff as part of green infrastructures. LID emphasizes conservation and use of on-site natural features to protect water quality. This method uses building and landscaping techniques to mimic the original hydrology of the undeveloped location, thus creating a sustainable water management system (1). 
         
 Examples of this type of design include vegetated swales, bioretention, permeable paving, constructed wetlands, green roofs and rainwater retention (2). In urban settings it is not uncommon to see 75% – 85% of the ground as being impervious to water. This means rainfall on this area will not permeate back into the ground in that spot but rather gather and become runoff. This runoff is traditionally collected via storm drains that will be carried away from the location where it originated. This removes the chance for that water to be purposed for things such as landscaping.  

To help those looking for help with the specifics or just more information Mesa provides a Low Impact Development Toolkit online. Mesa also features public examples of their efforts such as a bioswale that incorporates curb cuts in front of Mesa Urban Garden, 212 E. 1st Avenue.

With the many impervious roads, parking lots and roof tops in urban settings it makes tremendous sense to design these simple techniques for rainwater collection into municipal development plans.

References

https://en.wikipedia.org/wiki/Low-impact_development_(U.S._and_Canada) City of Mesa website: www.mesaaz.gov