Did you know that the average rainfall in the cities surrounding Phoenix (e.g. Scottsdale, Chandler, Gilbert, Glendale, and Tempe) only averages 8 to 10 inches per year?
Arizona is an arid region. Compared to the rest of the country, the rainfall of the Phoenix metro area cities is somewhat laughable. The adage, “but it’s a dry heat” describing a 112 degree day, came from this region. The local hot and dry conditions present some interesting facts regarding site grading and drainage:
- Many wonder why there are so few basements in homes in the Phoenix area. The reason is that we really have no frost line which is the depth to which soil freezes during the winter that forces the footing of the home to be dug deeper. If your zone is in a cold climate, the frost line will dictate that you must excavate further and dig a deep footing. The rationale is, that if we are already digging a deep footing, we might as well dig a little deeper and create more potential living space which adds value.
- Low rainfall totals allow local builders to construct homes with flat or low sloped roofs. Considering the home in the photograph above, runoff is routed to scuppers that simply dump water at the foundation area of the structure. Since there is no basement to flood, we get away with it here. This would not be acceptable in many parts of the country.
- Homes in the Phoenix area rarely have gutters and downspouts installed. Hey, it works here (most of the time).
- Builders often provide some form of drainage plan for the site but landscapers routinely mess it up. Once you close escrow, the next move is often to hire landscapers to beautify your property. Landscapers, though well meaning, are often not considerate of preserving how water behaves on the lot. They may fill in a retention area that is designed to hold water on-site so that it can percolate into the soil. Or they may reverse grade the soil around the home so that water flows and is held next to the foundation. More often than not, the landscapers get away with numerous grading mistakes.
- We even place our main electrical panels outside. Builders save a few bucks on the practice and flipping breakers at the panel has less chance here of being done standing in a puddle of water.
The above are some facts about grading and drainage that are different in arid regions. You must, however, keep in mind that runoff water sourced problems can and do still occur in the Phoenix area. We have countless stories about serious drainage problems and have served as an expert witness on these types of cases. During the home inspection process, if the professional home inspector recommends gutters it is for a reason. It is not because he or she believes they might look nice, they serve a purpose and can help mitigate drainage problems. Similarly, when comments are made in the home inspection report about grading problems around the structure, make these repairs a priority.
If you are buying or selling a home Chandler, or anywhere in the Phoenix metro area, Advantage Inspection Service provides professional home inspection services that can reveal if grading and drainage problems exist with the property.