Flooding at Harrold in Bedforshire

The foreground of this view is normally 90% field and 10% water. Flooding at Harrold in Bedfordshire

With all the terrible flooding the UK has been experiencing my thoughts have turned increasingly to what can be done to  moderate and reduce the damage caused by the torrential downpours and subsequent run off.

Of course many highly experienced and  qualified people are looking at this from  Town Planners to Landscape Architects and scientists. But as ever there is always room for individuals to consider an issue and do their bit. I thought a series (approx 400 words each) about rain gardens might be of interest and fun and will be an outlet for my research. I you have something you’d like me to research and report on do let me know in the comments below.

So what IS a rain garden?

Wikipedia says “A rain garden is a planted depression or a hole that allows rainwater runoff from impervious urban areas (e.g roofs, driveways, walkways, parking areas and compacted lawn areas) the opportunity to be absorbed.”

So it’s an area of absorbent but free draining soil, planted with tolerant plant species that can withstand the occasional and temporary flood.

Sounds simple enough and logical too.

Don’t all plants do this anyway?

Well the simple answer is NO. Some plants hate standing in water and even a few hours of it is enough to seriously affect their wellbeing. Other plants, on the other hand, LOVE a bit of soaked root action. Iris pseudocarus, Lobelia ‘Queen Victoria’, Veronicastrum virginicum and Coreopsis verticiliatta  to name but four. Trees too can be remarkable guzzlers of excess moisture with Betula nigra (River Birch), Liquidambar styraciflua (Sweet gum) and all manner of Salix (Willow) being favourites. The challenging part is that when there are not flash floods the plant may well have to cope with drought. Toughies only please!

It seems that there are also levels of rain garden with some areas more flooded  than others. So it makes sense to grade your plantings according to how long they are likely to be coping with excess water, or drought. Watery root lovers at the bottom of the dip, ‘friends of watery roots but not lovers’ closer to the normal garden or ground levels.

More questions I have – do add your own in comments below:

How much water can it hold?

What’s the science behind it?

Can I make one, if so HOW!?

Are there any locally I can look at?

Does it mean I don’t need to do other drainage stuff?

Is it legal? or do I need Planning?



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