artistic-drainWith the winter rains, it is a terrific time to evaluate your overall drainage system.  Is it working as it should?  Does the water flow away from the house foundation?  Or is it pooling/puddling somewhere in your yard?


Different scenarios require different types of drainage.  Almost every yard should have some sort of drain lines in place to prevent future issues regardless of the size of the property.


Consider the downspouts off of the roof line. These can be led into in a solid 3” styrene type of drain line and pitched underground to bubble up by gravity near the front corner of the property. Or they may connectdirectly into a pvc pipe which is cored through City sidewalk/curb and drains onto the street.


Any drain line should have a 1% to 2% minimum pitch for positive gravity-directed flow, so that the water drains out at the end of the line.  In simple terms, this would equate to a 1.2 – 2.5”” drop in every 10’ of run. Along this drain line should also be periodic inlets/grates that collect any surrounding areas. The yard should be graded in such a way that surface water from those specific areas slope into the drainage grates, and are fed into the main drain line.


There is an alternate type of drain line called a French drain. These are used at the base of  the soil side of retaining walls.  It is used to collect and move surface water that would collect at the base of a slope.  Or if the yard is sloped towards the house foundation, French drains can prevent water from flowing into a crawl space.



A French drain  system consists of perforated pipe that is surrounded by clear drain rock and enveloped in filter fabric that will prevent our clay/silty soil from clogging the drain rock.  The goal of the French drain is to catch water throughout a longer run, and lead it to a solid drain line, and spill out to the lowest point at the end of its run.


Water sitting in the wrong areas can drown plants, destroy lawn, shift retaining walls, and even lift concrete slabs.  Properly sloped patios, planting areas, lawns, and drainage behind walls are an absolute must have in a well-planned yard.

Proper drainage for your particular landscaping needs is essential.  Make sure your drainage system is designed properly and is working effectively. Call or click to contact Jennifer for your landscape needs includingdrainage consultation.

Contact Jennifer Craven, Landscape Design in San Francisco Bay Area