Topography, flow paths and sheet flow, surface, subsurface, French drains, perimeter drains, berms, bioswales, perk and infiltration rates are all important physical considerations to developing any substantial landscape architecture or garden design plan.
In consulting we often see the negative effects of lack of design planning and storm water engineering, like the ponding in the above photo. This occurred at the bottom of a slope, and nearby to a pool and patio that, upon examination, had insufficient drainage for its impervious surface area.
Mistakes like these often occur when several different contractors with mismatched skill sets and levels of competency are involved in a home improvement construction project on a property, instead of one unified design plan, project manager, and installation crew.
Soils and water table play a major role here, also the effects of development on adjacent properties. For example, water will pond faster in clay soils and/or with a high existing water table; if neighbors have a lot of impervious space and insufficient drainage, the sheet flow can be directed to your property. Proper drainage begins at the height of land, not the bottom of a slope. Locating, examining and inspecting all existing drainage utilities on a site should be an early priority. If ponding occurs, the area quickly becomes a mosquito breeding habitat — a nuisance and a human health risk.
Just as there are many ways to skin a cat, as they say (I don’t know why), there may be options to improving drainage depending on the degree of the drainage problem. Identifying water issues with infrastructure is a start. This means identifying water in the basement, existence of sump pumps, and examining gutters and leaders. Check out our FAQ How Do I Know If I have a Drainage Issue for tips. Often times, we can solve a landscape drainage issue with a multi-functional design feature such as a rain garden, an attractive garden feature with facultative native plants and the proper soil medium and depth to allow rainwater to collect and slowly percolate, while simultaneously providing pollen and berries for local wildlife. Check out our previous post on Rain Gardens.
If you have a water, drainage, or storm water problem, it is always better to address it sooner rather than later – contact us.
The past two years have produced unprecedented rainfall events especially in increased volume and frequency. If this is the new normal as a result of climate change, we are in for one hell of a ride! Plan for the future with a Storm Water Management plan.
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Jay Archer
Landscape Ecologist, Designer, President
Green Jay Landscape Design
914-560-6570