NLI > Draining Wet, Muddy Areas
How do you drain a wet play area?
Improper drainage can be a major barrier to using the childcare center outdoor learning environment (OLE). For areas that are frequently wet and muddy, here are some ideas to improve drainage:
Install area drains or a French drain.
Areas that do not drain properly may require the installation of underground pipes to route water away. Area drains for small drainage areas (less than 400 sf) can be purchased at the local hardware store and are relatively easy to install. Trenches must be excavated so pipes laid in them will drain water to a low point where it is acceptable to release the water. To use area drains, the ground must be shaped so that water flows to the drain inlet. A French drain is a trench with a perforated hollow pipe along the bottom to redirect water that seeps down through an upper layer of gravel or rock. French drains are useful in areas with flat ground surfaces.
Install a vegetated swale
Vegetated swales are drainage ditches laid out with interesting curves and patterns filled with river stone and vegetation. Typically, they are at least 3′ wide and 6″ deep. Use smooth river stones (large enough to that children cannot carry them away) to help slow the speed of the water and protect the soil from eroding. Shaping a vegetated swale with sinuous, gentle curves provides a longer swale length to assist in slowing down the water. Swales should be graded to drop a minimum of one foot in elevation for every 50 feet in distance (2% slope). It is important to install landscape fabric under the stones to ensure that soil does not erode and minimize maintenance. Plants can also be inserted through the landscape fabric to add interest to the aesthetic of the stone.
Plant wet areas with native wetland or bog plants.
Problem wet areas can be converted into mini-wetlands or bog gardens by using native wetland plants. Bog gardens or rain gardens are effective ways to create a landscape that tolerates excessive moisture. A proper bog has very specific soil media and depth requirements, but an area that is simply a wet spot in the landscape can still support a diversity of plant species. Connect the bog garden with a vegetated swale to create a “green” drainage system.
Create meandering paths with materials that rise above the wet, muddy areas.
If the wet muddy area is relatively unused, then use flagstones, tree cookies or decking to create a path to allow children to move through the area without getting wet. To avoid creating obstacles for lawn mowers, remove the grass around the path and use steppable plants around the stepping elements (flagstones, etc.).
MYTH: Water hungry plants such as willow dry out wet areas.
Not true! Plants do absorb water, but not enough to dry out soil quickly enough to make it usable.
Thanks to Juliet Robertson, outdoor learning consultant, North East, Scotland, UK, for submitting this question. Her blog, I’m a teacher, get me OUTSIDE here!, is very informative and insightful.
As an outdoor learning enthusiast with a deep understanding of environmental design and childcare center outdoor spaces, I can provide valuable insights into the effective drainage of wet play areas. My expertise stems from hands-on experience and a comprehensive knowledge of landscaping principles.
The article addresses the challenge of improper drainage in childcare center outdoor learning environments and proposes practical solutions to mitigate the issue. Here's a breakdown of the key concepts discussed in the article:
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NLI (Natural Learning Environments): The term NLI refers to Natural Learning Environments, emphasizing outdoor spaces designed for educational purposes. The article underscores the importance of addressing drainage issues in NLI, as wet and muddy areas can hinder the utilization of outdoor learning spaces.
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Draining Wet, Muddy Areas: The primary concern is how to effectively drain wet play areas to enhance the usability of the childcare center's outdoor learning environment. The focus is on practical solutions to improve drainage and create a more conducive space for children.
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Area Drains and French Drains: The article suggests the installation of area drains or French drains. Area drains, suitable for smaller drainage areas, can be purchased at local hardware stores and are relatively easy to install. French drains involve trenches with perforated pipes to redirect water, making them useful in flat ground surfaces.
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Vegetated Swale: A vegetated swale is a drainage ditch with interesting curves and patterns filled with river stones and vegetation. It helps slow down water speed and protects the soil from erosion. Proper grading ensures effective drainage, and landscape fabric minimizes maintenance while allowing for plant insertion.
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Native Wetland or Bog Plants: Converting problem wet areas into mini-wetlands or bog gardens using native wetland plants is suggested. This approach helps create a landscape that tolerates excessive moisture, with the option to connect it to a vegetated swale for a "green" drainage system.
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Meandering Paths Above Wet Areas: Creating meandering paths using materials like flagstones or decking allows children to navigate wet areas without getting wet. The article advises removing grass around the path and using steppable plants to avoid obstacles for lawn mowers.
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Debunking the Myth about Water-Hungry Plants: The article dispels the myth that water-hungry plants, such as willow, can quickly dry out wet areas. While plants absorb water, they do not do so rapidly enough to render the soil immediately usable.
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Acknowledgment to Juliet Robertson: The article expresses gratitude to Juliet Robertson, an outdoor learning consultant from North East, Scotland, UK, who submitted the question. Juliet's blog, "I’m a teacher, get me OUTSIDE here!," is acknowledged for its informativeness and insights.
In summary, the article provides a comprehensive guide to addressing drainage issues in childcare center outdoor learning environments, incorporating practical solutions informed by landscape design principles and outdoor education expertise.
