Landscaping & Design/retaining wall


I have a slight hill around 2-3 feet high at its peak, at the foot of the hill is a sidewalk that leads right to my pool. The hill keeps washing dirt into the pool at heavy rainstorms. I was thinking of building a wall out of railroad ties (landscape timbers) with drainage rocks behind it to prevent the mud slides. How would I go about doing this the right way, and how much drainage rock would I need?


Place drainage gravel no larger than 3/4 inch at the face of the wall. Make the width about 2 feet and take it to about 1 foot from the top of the wall. A drainage pipe placed at the bottom of the wall may also be helpful and to further aid drainage,place a swale at the top of the wall. Filter cloth placed behind the gravel may be a good idea to prevent silt from clogging the gravel.

Run rebar or threaded rod all the way through each of the timbers and/or nail  1 by 4 or larger pieces of treated lumber to both faces of the timbers,going perpendicularly to the timbers.

Heel the bottom of the timber wall into the toe of the hill and tilt the wall back a couple of degrees to increase the walls resistance to being tipped over. The wall must be anchored by "deadmen". These could be timbers placed perpendicularly to the face of the wall and anchored behind the wall with stakes or steel cables tied to concrete anchors. Hope this helps. Good luck.

Mark Harshman

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Design of landscape structures and design of planting arrangements in the landscape. I usually do not answer questions of a horticultural nature or about growing plants or gardening unless they are related to design. I will answer these questions at my discretion. I will answer maintenance questions at my discretion,usually when they are related to design. I am a landscape designer. I am not a contractor or a gardener. Although I will describe how something is built I do not provide detailed installation or construction instructions. Here are example categories of problems I can help you with: Design of residential walks,low walls,low retaining walls,fences,drainage systems,arbors,plant selection,xeriscapes (low water use landscapes),rain garden design,rain water harvesting,permeable paving,sustainable drainage. No advise on an architectural or engineering level. I DO NOT PERFORM ACTUAL DESIGN WORK THROUGH THIS SITE. I only provide suggestions and advice. For more comprehensive help check out my website at:


Landscape concept plan for a 30,000 square feet housing site. Involved site recon by pace measurements and photographs and a site analysis and a site analysis report and recommendations and a preliminary cost estimate. Design elements included canopy trees,shrub cover,accent flowers,trash receptacles,benches and planters. Landscape concept plan for a 7,000 square feet site for a community center. Involved site recon by tape measurements and photographs,a site analysis and the creation of 3 conceptual designs for the site. Work was done through a local professional design center. Design elements included tree garden,playground,sitting area,lawn,cooking area,lighting and concrete and brick paving. Landscape concept plan for a 3,000 square feet housing site. Involved site recon by tape measurements and photographs and a site analysis. Concluded in 3 concept designs for the site,shown at a formal presentation,a site analysis and recommendations. Work was done through a community volunteer program. Design elements included decks,a playground and fencing. Briefly as draftsman for landscape designer/gardener. Conceptual landscape design for residence. Involved site recon by tape and pace measurements and site analysis. Design included covered patio area,ground cover and flower beds. Two years experience as draftsman for transportation department in engineering firm and for engineering consultants to phone company. Duties consisted of plotting topography. Survey crew member. General assistant to surveyor. Work was done for U.S. Army and County Highway Department. No instrument work. Duties included tape measurement,holding graduated survey rod and plumb bob for sighting and clearing brush. Marketed Landscape Design Services. Brochure writing,promotional material and marketing graphics.

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From Civil Engineer: I am very impressed with your work and with the obvious thought you have put into the marketing of your venture. It was especially good to see a print of that job we discussed on the phone. I wish you much luck with the venture as I do with your plans for school. Im darn proud of you buddy. And by the way,when I get my license,maybe you will consider me for a consulting job down the road. I hope to get together with Rick sometime soon and I would really like to show him your stuff if its ok with you. From all these questions you ask I get the feeling that you are genuinely interested and have put alot of thought into the idea and process of landscape architecture and if you could possibly afford the cost I would urge you to take some classes in the areas you are most interested in. The subject is not so simple as it appears,mixing science and engineering with art and a certain amount of religion to create a comfortable and pleasing balance between man and nature. A thoughtful soul like yours can do this but it can be a lifes work getting it right.

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