SFGate

Amy Martin Landscape Design Could you post some pictures of it as it is?

nancy22032 You might terrace the hillside to stop downhill drainage. You would need a pro to plan it and there are some type of drains that could be installed. I would urge you to take action quickly before your house is damaged.

olldbobbi Nancy is right, terracing is the best idea. Well placed plants and hardscape will do a lot for your slope.

ASVInteriors I have been down this road (so to speak)
The problem is that if it is very steep there is a risk that there will be a landslide as more and more water filters in. Those deep crevices are not a good sign. Some kind of wall retention may be required.

The other solution is plant with shrubs that have a good root system and that grow fast - the best (depending on your area) is a purple willow which has an amazing root system, is pretty hardy but will need regular pruning (every 2-3 years).

However, I would only proceed with this plan of action once you have checked with a landscaper or even your local council.

Ironwood Builders Landscaping hillsides is a challenge. Retaining walls to prevent erosion and create level planting areas are a common way to deal with the problem. Managing surface water requires proper planning and a good drainage system.

Here in earthquake country, retaining walls of over three feet require engineering, so the solutions I'm posting are for walls below that height.

The engineer on a recent job told me he did not require drainage behind an earth filled, dry laid stone wall (less than 3') because the gaps between the stones allow surface moisture out and disperse its force. A timber or concrete retaining wall is subject to hydrostatic pressure...the build up of water laiden soil behind the wall. To prevent this from happening and blowing out the wall a perforated pipe is laid inside a geotextile fabric "bag" filled with 3/4" drain rock at the bottom of the wall or slightly lower. Weeps through the wall and hooked to the drain pipe allow the water through and disperse large flows. If there is a natural declivity that collects water a larger pipe is required to divert and control that water. That level of drainage must be designed by a civil engineer. Alternatives to the filter bag exist. Caltrans, our highway department, has engineered a permeable fill that does not require a filter bag. Caltrans Class II fill is dropped in the trench, pipe laid and topped off with the Class II. Concrete retaining walls benefit from the use of a weep fabric, a plastic, dimpled moisture barrier that is covered with geotextile filter. Waterproofing mastic is placed on the back side of the wall and then the drain mat is attached to the vertical surface. The same pipe and drain system goes at the bottom of the wall. Water hitting the drain mat runs down the wall and hits the pipe. If dispersing the collected water is not a good idea, say there is a neighbor below or your house would be on the receiving end, terminating pipes well outside the living zone is an option. A rock lined basin and a 'tee' fitting at the end of each pipe to disperse the water force is a good idea. We don't use flexible perf pipe. The stuff fills up with silt no matter what and the clean out risers we install for drain snaking do us no good. All hard pipe is good, perforations down! Hope this helps!

Dytecture Agreed, definitely have an engineering or professional landscaper do a proper retaining wall and drainage so the yard stays intact over time.

olldbobbi Everyone, would a French drain work in this situation?....Bobbi

Ironwood Builders A French drain is a debated topic. In the east it means a filtered rock filled hole that water is sent to for slow dispersal to the underground aquifer. In the west, many call underground perforated drainage "French" drains. As water becomes more of a pressing issue, collecting and saving surface water will become more advantageous. At one time, most homes on small properties in the Midwest collected all rainwater in an underground tank and had a pump to pull landscape water out. Cistern systems are beginning to be installed for roof and foundation drainage and for gray water retention in many larger projects in the west.

olldbobbi David! You know too much! More than I can follow, anyway :))

Ironwood Builders bobbi...twenty five years, four states (counting the years I worked with my dad and brother in law as states but not years) three houses from fixer to show home (two and a half, sell it when I finish or die). Oh yeah...and keeping my eyes open and mouth shut while the real pros did their magic. And yes to reading up and studying my field...au courant. Passion for houses and building, art and architecture. A mind is a terrible thing to waste.

simplify52 Hahaha, Bobbi! I was thinking the very same thing. Ironwood Builders is VERY knowledgable. I wish we had him here in Florida. I ALWAYS learn so much from him. Thank you, Ironwood!!!!

olldbobbi Awww, Kathy, that's so nice!

Arlene Warda, Architecture+Interior Design Hi Susan, I agree with terracing the retaining wall first, with a civil engineer, and then landscape architect. The terraces are a wonderful starting point. One can have inspiration to start gardens on each level. A water feature, in form a a waterfall, could be incorporated at the lower tiers or a trough of water. It has a noise differal and if cars go by, once in awhile or at certain hours of the day you might turn on the waterfalls for noise differal. Also the bottom tiers you may have fun with herbs, an herb garden or vertical herbs! a nice project and one you can use!

I can't wait to see your 'before' and 'after' pictures. Thankyou.

Ironwood Builders You all are welcome...I have a tremendous debt...and no pay back is possible...paying forward is my only option. I hope my communication and knowledge help and not hurt...