Children and water, Boston
January 30th, 2019 by Mark Laurence

The safety of children and water is potentially a controversial issue and I want to make it clear from the start that these are genuine thoughts, with genuine intent but please don’t try and hold me liable for any disasters or accidents that may befall you or your loved ones. I cannot be responsible for your life and any decisions you make on this issue are yours alone. I naturally hope and intend that only good and positive benefit can come from this writing.

Children have an almost universal fascination with water, and parents an equally almost universal fear of it, or of their children being near it. We have all heard the horror stories of children drowning in a pond, or even a shallow puddle and our hearts go out to those unfortunate few who have suffered such a fate.

children enjoying the water

Children enjoying the water

But we seem to live in a fear-driven compensation culture, which stifles creativity or adventure because of the risk of hurt. Authorities and companies cannot afford to take risks, or allow other to take them. Consequentially, more and more things get banned in the interests of public safety. The world may be safer as a result but it is certainly blander.

As a young child I would walk the suburban mile or so to school on my own, ride my bike to visit friends, play down at the dump, swim in the sea and generally have freedoms many children are not now able to experience. But creative play is an essential part of a child’s development and must be catered for somehow. A love and respect of water should be encouraged and this requires contact and familiarity with it. I believe that those most at risk are those who do not appreciate the dangers and those who are too young to.

A burst watermain in Iraq

Out of the disaster of the Iraq war, this burst water main provides a moment of joy for children and adults alike.

It is true, of course, that much of this familiarity, or lack of, will be caused by the geography of your environment. If you don’t have water in daily proximity, it is hard to become familiar with it. If you don’t see with your own eyes how a little stream can become a raging torrent after a downpour, then you will not be aware of the potential danger. Knowing the dangers brings about respect, gives us boundaries beyond which we know that things aren’t safe. In urban areas, the increasing use of WSUDs (water sensitive urban design) in the form of swales and rain gardens is a positive development.

There’s another good reason for us to have regular contact with water and that is a biophilic one. Water is a vital element, which, through modern living, we now tend to regard as no more than a right of utility. But water is the life force of the planet, and so of ourselves. Why else would we want it in our gardens? It soothes us, distracts us from our cares, puts us in touch with those deeper fundamentals of life, if we but let it. Children who experience this often can only be better off for it.

Children playing in a rain garden
Children playing in a rain garden in their family home. When dry, this is empty.

So if I’ve convinced you that it’s good for children to experience water, let’s think about how we might do so with some safety. First of all, young children should be supervised by an adult or responsible elder child, that goes without saying. I don’t advocate that you leave them alone.
I don’t know if there are any statistics available as to the ages of children that have accidents with water, but parental sense will tell us all that children under five have little comprehension of danger and must be watched very carefully, as must those of all ages with special needs. Water features should perhaps be fenced off while children are in their early years.

If there’s not much you can do about water in your wider environment, then you can perhaps create a feature in your own garden.

pond profile showing gentle slopes

This drawing of a stream cross-section could also be for a small pond. Pebbles and shingle make a good base, which the children can play with. Shallow water with gentle slopes mean that if they fall over, they can stand up and climb out.

Steep sides are the most dangerous aspect of a water feature, preventing children (and animals) from being able to stand up or climb out.

Loose paving on the edges of ponds is another risk factor; use only large slabs or stones and make sure that they have only a small percentage of overhang, and are securely cemented in place. Better yet, use a pond-edge design style which doesn’t use paving in this manner at all.

safe play with water

A reminder of what it’s all about – fun! Don’t do this on paving which may become slippery and prevent algal build-up.

With gently sloping sides, layers of subsoil, gravel or shingle will protect the pond liner and give good grip for feet and hands – bare liner tends to be slippery and is more vulnerable to damage. Good construction helps all round, although that is not the subject of this article. If you have an overhanging deck, make sure the water is not too deep at this point and that children can’t get trapped underneath it. Metal or plastic grids can also be built into a pond, sitting just below the water level. These need careful thought as to their siting as they must take the weight of a person without breaking. The danger is these can look very industrial.

As a final thought, if you want moving water but don’t want the depth of a pond, consider a stream garden, where water just flows along a shallow water-course. There is no pond as such and the water just disappears underground into a hidden sump tank, which houses the pump and which is inaccessible..

a stream garden

This stream feature is used by children – the water barely laps their ankles. Stones are moved, small dams made…

In conclusion, there are many things that children learn from playing with water: self confidence, balance, awareness of danger, responsibility, experience of wildlife and of Nature’s rhythms. A careful and reasoned approach is what is required for allow a child safe, creative exploration.

And of course, we adults are all children at heart, too. Play safe.


First published in 2009, updated 2019

Posted in Biophilia, Design, Garden Design, landscapes, Ponds, rain gardens, Water Gardens Tagged with: , , , , , , , ,

Vertical flow pond biofilter
January 21st, 2019 by Mark Laurence

The maintenance of ponds is the one thing that people seem to be the most uncertain about – it seems shrouded in myth and confusion.

A biological filter can be as simple and as beautiful as this.
A biological filter can be as simple and as beautiful as this.A biological filter can be as simple and as beautiful as this.

Some of this is basic ignorance of simple biological structures but this is enhanced, in my view, by the profession’s over-mechanised solutions to obtaining clear water. There is also a tendency to think that a bottle of some substance can perform miracles and solve unclean water problems – but it can’t.

First lets be clear (pun intended) there is a difference between clean and clear water. A pond’s biological functioning might be quite happy with water that is healthy but carries an amount of suspended solids. The health of water is far more dependent upon keeping levels of Nitrites, Nitrates and Ammonia low; these have nothing to do with water clarity.

Our aesthetic taste demands clear water, however, and it is certainly true that pure, clean water is always the most beautiful to behold.

To obtain and keep clean and clear water, we must keep the pond in balance, so a simple understanding of water balance is useful. This involves two things; mechanical filtration to remove solids, and bacterial action to remove pollutants.

First, let’s dispel a few commonly held myths:

  • You need a magic filter box with lots of plumbing entrails
  • You need something called an Ultra Violet filter
  • You need to test the water frequently
  • You need to change a percentage of the water at intervals

A filter box gives some mechanical filtration of solids and creates a home for micro organisms to do their work. It is these bacteria that convert Ammonia into Nitrites then into Nitrates, and they are naturally existing in any aquatic ecosystem. Thus it is not the filter box that does the majority of the work but bacteria already present in the pond.

An Ultra Violet filter kills algae, which cause green water. Algae feed on nutrients available in the water – remove the nutrients and you solve the problem at source. This may be an oversimplification, but it is fundamentally true. A UV filter is therefore treating the symptoms, not the cause.

I have rarely found a situation where tests have told me anything that my eye has not. That’s not to say that tests do not have their uses but I would suggest that you can observe when a system is out of sorts. Nature is incredibly good at correcting imbalances, given a chance.

Ponds are an open system and will always lose water through evaporation, so some new water is always going to be added via the garden hose or a top-up system, preferably from harvested rainfall. Water change regimes are quite unnecessary and probably unhelpful to establishing a balanced system, which has to start again each time this is done.

It is true, however, that small garden ponds are often unstable in terms of quarter quality, for the following reasons:

  • The water body is too small to maintain a stable and permanent ecosystem
  • Water levels and temperatures fluctuate widely – small isolated ponds would naturally dry up
  • Fish stocking levels are usually too high, creating biological overload
  • There are insufficient plants and bacteria-rich medium to ensure a healthy biological cycle
This small rill incorporates a bio-filter alongside the wall. Spouts pour water into the filter, where it is cleansed before being passed back into the rill.
This small rill incorporates a bio-filter alongside the wall. Chutes return water to the rill, having been drawn down through the biofilter.

All this adds up to one thing: excessive nutrients in water, leading to algae growth, lack of oxygen, cloudy water – in the end this leads to eutrophication.

You have to remember that the average sized garden pond is a mere puddle in Nature’s terms. Ponds of that size would likely be impermanent and support little life, other than in a temporary or cyclical manner. In summer a small pond would dry up unless it were fed by a stream or high water table. If it were fed by a stream, then the pond wouldn’t be a pond – it would be a bulge in the water course.

We must accept, then, that the garden pond is a highly artificial environment, which needs some help in order to remain attractive to us, and to its inhabitants. What form should that help take? Where space is severely restricted, a filter box may be the answer, for it crams a lot of bacterial housing into a small space.

The same can be done, however, by the use of natural biological filtration, which is designed to be an attractive feature of the water garden itself, rather than a utilitarian box than must be hidden. In its simplest form, this can be no more than a gravel filter bed built into a stream which feeds the pond. Planted with suitable aquatic plants, this can be a major feature and is also good where hungry fish tend to devour plants placed in the main pond.

This filter bed is built into a stream feeding to a pond

This filter bed is built into a stream, flowing, right to left, which is pumped from a pond, to which it returns. The filter becomes an integral part of the overall design, forming an important aesthetic feature.

How big should such a feature be? Natural filtration is an inexact science, so the bigger, the better. A surface area of one quarter to one third of the pond surface area is a good guide. A more intensive system uses a vertical, rather than horizontal flow. These have a much higher cleansing rate and so can be made smaller, thus saving space. However, they are somewhat more complicated to construct. These operate on a similar principle to the plastic filter box but again, they have a huge aesthetic advantage.

I have hardly scratched the surface of this fascinating subject, but the main point is that you are helping Nature to do what she does already, rather than taking control with technology.


First published in 2008

Posted in Design, Ecosystem Services, Garden Design, Ponds, Water Gardens Tagged with: , , , ,

A stream runs down to the pond
June 16th, 2015 by Mark Laurence

I have been lucky enough to have designed and built a lot of water gardens in my time; I’ve been looking back over some of my pictures, and thought I’d share them here. ¬†Working with water is like nothing else; it is enigmatic, frustrating, contrary, exciting and absolutely rewarding in a way that few other mediums can be.

A Naturalistic pond with simulated wetlands and planting

A Naturalistic pond with simulated wetlands and planting

Pond bio-filters clean the water, naturally

Pond bio-filters clean the water, naturally

A stream runs down to the pond

A stream runs down to the pond

A stream runs through a gravel-garden

A stream runs through a gravel-garden

A bridge of sleepers over the stream

A bridge of sleepers over the stream

A gentle waterfall emerges from within willow bushes

A gentle waterfall emerges from within willow bushes

Posted in Design, Environment, landscapes, Ponds, Water Gardens Tagged with: , , , , , , ,