Dealing with the issue of climate change in the context of food production, the stability of agricultural ecosystems, I have noticed that there is very little discussion of the two key pieces of this puzzle. Soil and water form the basis of food production around the world In addition, they are inextricably linked by interrelationships that permeate each other – water shortages accelerate soil erosion, excess water also intensifies soil erosion, soil deprived of organic matter loses its ability to store water and gradually turns into a desert.

A desert devoid of vegetation cover stops bringing in rain and eventually there is even less water. Climate change is increasingly affecting the quality and availability of water, and this translates into the quality of the vegetation cover in an area, and thus the quality of the soil, on which yields also depend. Even more intensified connections are observed in urbanised areas. The tendency to cover living soil with water-impermeable surfaces is nothing less than the transformation of an area into a hydrological, soil and biological desert. The widespread ‘concretisation’ is consuming more and more land, generating a heat island effect, drying out the air, eliminating conditions conducive to rainfall, preventing water infiltration into the ground and thus the ability to regenerate water resources hidden in geological formations. On the other hand, looking at urbanised areas, one can see that cities continue to grow and, consequently, the demand for water in them increases. Water that is becoming increasingly scarce. This is why it is so important to take all practical measures for water retention, both in agricultural spaces and in areas characterised by a strong degree of urbanisation.

A broad area providing numerous solutions to the above problems is landscape water microretention. It should be understood as taking a series of measures to store water in multiple locations simultaneously. The implementation of micro-retention solutions improves an area’s ability to mitigate the negative effects of climate change and increasingly violent weather events, such as prolonged droughts or short-term, torrential rainfall leading to flooding events. Within rural areas, micro-retention solutions should be implemented on soils of the lowest quality class. Within urban areas, micro-retention should be a common feature in the landscape of all urban agglomerations.

Solutions such as pocket wetlands can be an element that slows down vehicle speeds on residential streets and can successfully replace speed bumps while providing multiple functions and ecosystem services. They can even be created as permanent green roof elements on existing buildings. Ecological puddles, drinking troughs, ponds and ponds should be located in any depression in the landscape where water naturally collects. In areas with slopes between 5 and 25%, passive, contoured ditches should be introduced to slow down surface water run-off. Such ditches run perfectly horizontally in the landscape (mimicking the position of contours marked out in the field), are laid across the slope, thus cutting the surface runoff of water, providing temporary storage high in the landscape, and by extending retention time allow water to infiltrate deep into the ground. Similar solutions supported by linear tree plantings are equally effective in hilly and mountainous agricultural areas. In the remainder of this article I will focus on just three solutions from the micro-retention repertoire and these will be pocket wetlands, ponds and ecological puddles.

Pocket wetlands

Pocket wetlands are a practical tool for micro-retention of water, designed mainly for implementation in highly urbanised areas. These types of structures can be located close to streets, as a permanent element of large car parks and even as traffic slowing islands. The construction of pocket wetlands as permanent elements of roads, roadsides and car parks requires the appropriate permits, water rights and building permits, but this category includes solutions that any of us can create in our own garden or on a neighbourhood lawn without any permits. I am referring here to pocket wetlands that function as drinkers for animals (amphibians, reptiles, birds and insects). The construction of such a drinker is very simple. We start by choosing a suitable site. I recommend choosing a location that provides access to direct sunlight in the morning and afternoon and provides deep shade around midday. It is sufficient to hide such a drinker behind a bush planted on the south side and with open space on the east and west side. The next step is to dig a pit of about 2 m2 in an outline resembling a slightly curved bean seed. The maximum depth of the dug-out basin is 60 cm. It is best to dig such a basin in a location where there is solid clay in the subsoil. Once the trench has been dug, it only needs to be firmly compacted to provide a good waterproofing to keep the water in the basin for a longer period of time. If you are digging on sandy, easily permeable ground, the resulting trench must be lined with a layer of about 10 cm of clay or bentonite clay. Personally, when designing and setting up such watering troughs, I try at all costs to use materials of natural origin and to avoid introducing plastics into the environment, such as films or plastic formats in the shape of miniature ponds. If we already have a sealed basin, the next layer is coarse sand, into which we will plant plants native to the wetland, such as water mint, watercress, water lily, marsh forget-me-not, etc. Reach for native and locally occurring aquatic and wetland plant species. After planting the plants, place a few large, flat stones in the central part of the basin and sprinkle the remaining areas, also around the plants, with crushed charcoal. Finally, we place patches of moss on top of the stones occupying the central, central space and fill the basin with rainwater. The pocket wetland created in this way will be an ideal resting place for small animals looking for a safe source of water on hot days. These types of drinkers are also ideal for pollinators. They can also be located close to desPocket wetlands are a practical tool for micro-retention of water, designed mainly for implementation in highly urbanised areas. These types of structures can be located close to streets, as a permanent element of large car parks and even as traffic slowing islands. The construction of pocket wetlands as permanent elements of roads, shoulders and car parks requires the appropriate permits, water rights and building permits, but this category includes solutions that any of us can create in our own garden or on a neighbourhood lawn without any permits. I am referring here to pocket wetlands that function as drinkers for animals (amphibians, reptiles, birds and insects). The construction of such a drinker is very simple. We start by choosing a suitable site. I recommend choosing a location that provides access to direct sunlight in the morning and afternoon and provides deep shade around midday. It is sufficient to hide such a drinker behind a bush planted on the south side and with open space on the east and west side. The next step is to dig a pit of about 2 m2 in an outline resembling a slightly curved bean seed. The maximum depth of the dug-out basin is 60 cm. It is best to dig such a basin in a location where there is solid clay in the subsoil. Once the trench has been dug, it only needs to be firmly compacted to provide a good waterproofing to keep the water in the basin for a longer period of time. If you are digging on sandy, easily permeable ground, the resulting trench needs to be lined with a layer of about 10 cm of clay or bentonite clay. Personally, when designing and setting up such watering troughs, I try at all costs to use materials of natural origin and to avoid introducing plastics into the environment, such as foil or plastic formats in the shape of miniature ponds. If we already have a sealed basin, the next layer is coarse sand, into which we will plant plants native to the wetland, such as water mint, watercress, water lily, marsh forget-me-not, etc. Reach for native and locally occurring aquatic and wetland plant species. After planting the plants, place a few large, flat stones in the central part of the basin and sprinkle the remaining areas, also around the plants, with crushed charcoal. Finally, we place patches of moss on top of the stones occupying the central, central space and fill the basin with rainwater. The pocket wetland created in this way will be an ideal resting place for small animals looking for a safe source of water on hot days. These types of drinkers are also ideal for pollinators. They can also be located near drains of rainwater flowing from gutters or flowing from rain gardens set up in containers.zcz water flowing from gutters or flowing from rain gardens set up in containers.

Waterholes

These are small reservoirs with an area of up to 50 m2 and a depth of no more than 1.5 m, most often created in home gardens. The construction of such a pond requires only a water-legal notification, so every owner of a house garden can realise this element of micro-retention within the development of their own property without any major obstacles. When building a pond, I also encourage the use of natural materials for waterproofing wherever possible. The construction process is very similar to building a pocket wetland. The difference is a larger and deeper excavation and more opportunity to plant the marginal zones with a variety of vegetation. When building a pond, it is very important to maintain good water quality by ensuring internal water circulation and adequate aeration. For this purpose, we have a great variety of solutions available, such as aeration systems, water circulation pumps, cascades and aeration basins. Whenever I go for technological solutions, I always make sure that they are solar-powered and can withstand extreme weather conditions (e.g. winter operation and resistance to wet conditions). A very aesthetically pleasing and interesting solution for water circulation and aeration in ponds are aeration bowls, called flow forms in English. They form a cascade on the edge of the pond in which the individual bowls set the flowing water in a figure-of-eight motion that promotes good oxygenation of the water. In combination with a small pump powered by a photovoltaic panel, they create the ideal solution for domestic ponds. When choosing plants for the pond it is advisable to opt for a high level of biodiversity and include plants for the pond rim, shallow water zone, suspended and floating plants. Here, too, we should use native species such as pondweed, broad-leaved clubmoss, common reed, bulrush, water mint, floating salvinia, water nut, hornwort, bulrush, water lash, etc. Such a selection of plants will ideally filter the pond’s surface and provide a good habitat. Vegetation selected in this way will perfectly filter the water and maintain its high quality.

Ecological puddles

Ecological puddles are shallow microretention basins with an area of less than 150 m2 and a depth of no more than 1 m. A characteristic feature of ecological puddles is their periodicity. That is, they fill with water during heavy rains, store it and then gradually release it into the environment through evaporation and infiltration (soaking into the ground). They are usually created in areas without drainage and are planted with vegetation resistant to periodic water shortages. Due to their size, their construction requires the use of heavy equipment and, consequently, professional design and the appropriate building approvals and permits. Nevertheless, they are an ideal solution that can be implemented as part of so-called participatory or civic budgets. It is therefore worth making every effort to encourage the implementation of such solutions both in large urban agglomerations and in smaller municipalities located in rural areas.

Author: Łukasz Nowacki

The text was written as part of the project „Hydrozagadka – how to win against drought?”