Friday 26 August 2022: Three Affinity Water Articles

Friday 26 August 2022: Three Affinity Water Articles

Where our water comes from

We take the majority (65%) of our supply from groundwater sources and the remainder from surface water sources, including from the River Thames and from reservoirs located outside of our supply area. We also receive water from and provide water to neighbouring water companies (known as bulk supplies or transfers).

Groundwater makes up an important part of our water supply, and this is the area we focus on most when assessing our water resource situation and the risks of drought. Please see our Drought Plan for more information about how we monitor our water resources and how we plan for when these are affected by low rainfall. 

The groundwater we abstract is stored naturally underground in bodies of rock known as aquifers. These aquifers also contribute to flow in the globally rare Chalk streams in our area. 

We work hard to ensure we monitor and mitigate the impacts of our abstractions on the local environment. This includes reducing certain abstractions, both temporarily during times of stress and in the longer term through our sustainability reductions programme. We also provide river support or augmentation during times of low river flows in some rivers. Our programme of river restoration, which aims to deliver significant habitat enhancements on rivers across our supply area is helping to improve our rivers for local wildlife. For more information about these programmes please see our Drought Plan. We face many challenges including population growth and climate change and are actively planning to create a secure and environmentally sustainable water supply in the future. For more information about the plans we are putting in place to meet these challenges, please see our Water Resources Management Plan.

In summary, what was this article telling you?​

How easy or challenging was it to read and understand?​

What would you change, if anything, about this article, and why?

This article offers a cursory overview of how Affinity Water obtains its fresh water.

I did not find it remotely challenging. However, I considered it to be written for well-educated people, not for the general public. It uses technical words, such as groundwater and abstraction, with which the general public is unlikely to be familiar and may feel as though they are being made to appear stupid. It uses terms, such as mitigate and enhancement, which whilst entirely familiar to educated people, whose use of language involves 'elaborated code', will be much less familiar to less-well-educated people who spend their lives immersed in a local or sectoral 'restricted code'. The sentence construction is also intended for an educated readership. The thrust and flow of the article feels disjointed. I would wish to rewrite the entire article.

Why winter rain is important

Due to the nature of groundwater and how it functions, the most important factor is rainfall during autumn and winter, when groundwater levels are effectively topped up by the rainfall that percolates down through the soil. This process is known as recharge. The ground needs to be wet for water to seep through and for recharge to happen, and we measure this through a metric called soil moisture deficit, or 'SMD'. The higher the SMD, the drier the soil is and the less likely it is that rainfall will permeate down to contribute to recharge of our aquifers. Conversely the lower SMD is, the more likely it is that a higher proportion of rainfall will contribute to recharge.

Summer rainfall has little impact on Chalk groundwater levels because the ground is hard and dry, which makes it difficult for water to get through, and a large proportion of it runs off into rivers or the drainage network. Water falling during warmer months is also more likely to be used by plants/vegetation or evaporate.

1. In summary, what was this article telling you?​
2. How easy or challenging was it to read and understand?​
3. What would you change, if anything, about this article, and why?

In summary, the article explains why winter rain is important to water companies

As with the first article, I found the material easy to understand. As with the first article, I consider it poorly suited to a less-well-educated readership, for exactly the same reasons. Is it your intention to inform, or do you really wish to teach? ".. we measure this through a metric called soil moisture deficit, ..." This kind of language can make less-well-educated people angry - I speak from experience. I also note that the verbs percolate and permeate are used as if interchangeably, whereas they mean different things, which is relevant in the context of this article. As with the first article, it reads clumsily.

How droughts affect our water supply

Droughts vary from region to region in England. Neighbouring water companies will take the actions that are necessary in their region to protect water supplies and this can mean that our actions may differ according to the particular circumstances.

The reasons why water companies may have to react differently in terms of restrictions, and the timing of implementation, are explained below.

Droughts can vary in severity across a region, depending on rainfall patterns, with some areas experiencing more rainfall than others, and therefore causing different levels of water shortages across the region.

Drought can also impact water companies differently depending on how their water supply systems are made up. Water companies divide their supply regions into smaller areas known as Water Resource Zones (WRZs). WRZs can be divided into those dependent upon: 

• Groundwater abstraction
• Surface water - river abstraction
• Surface water - reservoirs filled by abstracting local river water or by impounding river water 
• Combinations of the above.

Each of these types of water sources undergoes a different risk at different times during a drought event. This mix of WRZ types means that even if there were not a significant difference in drought severity across the region, WRZs will tend to react differently to the same drought. That means in similar drought conditions, rivers, groundwater sources and reservoirs across the region can respond differently in terms of risk to supply.

For example, a WRZ dependent on combined river abstraction and reservoir storage for supply may have a different level of risk to one based on groundwater abstraction. This difference in WRZ vulnerability has an impact both at the company level and regional level. This means that we could apply temporary use restrictions across some areas of our supply, but does not necessarily mean this will cover our whole supply area. Equally the need to impose restrictions for one company may not equally apply to another. For more information about how droughts can affect us as a predominantly groundwater-based company, please see our Drought Plan.

1. In summary, what was this article telling you?​
2. How easy or challenging was it to read and understand?​
3. What would you change, if anything, about this article, and why?

In summary, the article addresses why water company responses to drought conditions vary between water companies and between different areas within the same catchment.

The language in this article is, as the other two, intended for an educated readership "... us as a predominantly groundwater-based company." (Do you seriously imagine that a customer who has a few mediocre GCSEs will make meaningful sense of that terminology?). How are people supposed to know and understand the difference between "a drought event" and "drought conditions"? However, in contrast to the other two, it is better written and more coherent. It still has some conceptual problems, including determining whether the article is intended for a textbook or a public information sheet.

I have responded honestly to what I have read. Part of my job used to involve copy-editing PhD theses and textbooks for publication. Please forgive the hubris: I would willingly edit these three articles.

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Here is my attempt to rewrite these passages:

How water companies get fresh water

When rain falls onto the ground, it starts to wet the soil. Soil acts like a sponge, and can fill with water. Plants growing in the soil take up water through their roots. Once the surface of the soil becomes wet, the rainwater starts to sink deeper into the soil. Below the soil is rock. Some kinds of rock, such as chalk and sandstone, allow water to pass into and through the rock. Other kinds of rock, such as granite, do not allow water to pass into rock. As with soil, chalk and sandstone act like a sponge and can fill with water.

When it rains, water sinks through the soil only slowly. Where there is a rock such as chalk or sandstone beneath the soil, the water sinks ever deeper into the rock, but only very slowly. After months of rain, the rock gradually fills with water. A water well is a hole dug deep into the rock that has filled with water - water that has seeped out of the rock into the well.

Chalk and sandstone are excellent at gathering water that has sunk into the ground. Water companies, such as Affinity Water, drill deep holes into the chalk and sandstone. Water in the rock seeps into these holes. This water is then pumped out of the holes, cleaned and put into the mains water pipes. Affinity Water gets two thirds of its fresh water from water stored in rock.

When a lot of rain falls onto the ground very fast, instead of only sinking into the soil, much of the rain runs off the soil and forms streams. Instead of sinking into the rock beneath the soil, much of the water in the soil trickles into the streams. Streams meet, join together, and become rivers. Water in rivers flows to the sea. Water in rivers is fresh water, and can be cleaned for people to use. Water in the sea is very salty, and cannot be used. Water companies take water from rivers, clean it and put it into the mains water pipes. A river has to be big for much water to be taken from it.

One way to gather a lot of water in one place is to dam a river and create a reservoir. A reservoir usually looks like a lake, and can hold a lot of water. Reservoirs are especially useful in places where there is no chalk or sandstone beneath the soil, such as places where the rock is granite instead. Reservoirs are very expensive to build, and often destroy the homes of wildlife. In the past, entire villages have been swallowed up by a new reservoir. On the other hand, larger reservoirs often offer the opportunity for water sports. Affinity Water obtains one third of its fresh water from rivers, such as the River Thames, and from reservoirs.

Drought

Drought is when there is persistent lack of water. Mostly, we think of drought as being a lack of rain over a long period of time. River water flow slows, and parts of the river might even dry up until it rains again. The level of water in reservoirs gets lower, and the reservoir risks becoming empty. Drought can also occur when the water stored in rock, such as chalk or sandstone, becomes used up. Weeks or months with little or no rain can become a problem when fresh water is mostly drawn from rivers and reservoirs. This is because rivers and reservoirs mostly rely on rain that has recently fallen on the ground or sunk only into the soil. Water stored in rock may have been there for years, and is less vulnerable to periods of low rainfall. There may be less of a problem when fresh water is mostly drawn from deep holes in water-storing rock. 

Weather in Britain often involves a dry summer and a wet winter. Rainy winters recharge water-storing rock with water. This means that, as long as there has been good rainfall in the winter, there will be plenty of water to draw out of the ground even during a dry summer. A dry winter followed by a dry summer can become a problem. Hot, dry summers are the worst. High temperatures bake the soil, forming a kind of crust. This makes it more difficult for the water to wet the soil, and so sink down. Instead, the water simply runs off the very dry ground straight into streams and rivers, sometimes causing flooding. Summer rainfall rarely reaches the underlying rock.

Water companies have Drought Plans that describe what they will do when there is a drought. The best-known action is to ban the use of hose-pipes in order to reduce water use by customers. However, there are many other actions that can be, and are, taken. Affinity Water's Drought Plan can be read in detail online. A water company that obtains its fresh water from rivers and reservoirs might need to implement its Drought Plan sooner than a water company that obtains its fresh water from water stored in underlying rocks. On the other hand, Kielder Water in Northumberland holds so much water that it would be hard for it to run dry. 

Southern and eastern Britain tend to experience less rainfall than northern and western Britain. This means that water companies in south-eastern England may have to activate their Drought Plan sooner than water companies further north or west. Low rainfall during 2022 has meant that South West Water reservoirs, whilst almost full to capacity in March, had fallen to 40% capacity by the end of August. Unlike Affinity Water, South West Water obtains 90% of its fresh water from rivers and reservoirs, and have had to impose a ban on the use of hosepipes. Different circumstances mean that different water companies activate their Drought Plans at different times. 

Protecting the water supply

Water companies do not only supply fresh water. They are also required to protect the water resources. They look after rivers, reservoirs and water stored in the rock. Rivers are places where wildlife can flourish. If too much water is taken out of a river, wildlife suffers. Sometimes water is pumped into rivers to protect the wildlife. Reservoirs are also places where wildlife can flourish, and are often used for recreation, too. Drought can be bad for a reservoir. Water stored in rock can be threatened, especially by ever-increasing demands from new housing estates and from industry. Over the years, winter rains may be insufficient to recharge the rock with water, until it eventually dries up. On the other hand, when there is plenty of winter rain, the level of water in the ground may be high enough to to allow winter streams to flow, and to keep chalk streams flowing along their full course.

Technical terms used in the water industry

Run-off: water from rainfall that runs over the ground into streams and rivers.

Groundwater: water that sinks into rocks such as chalk, limestone and sandstone.

Aquifer: a body of rock that holds water and can be used for water storage.

Borehole: a hole drilled down deep into the rock, and can be used for pumping water out of the rock.

Abstraction: taking water from rivers, reservoirs and aquifers to use for fresh water supply.

Water table: the exact depth below which the water-holding rock is filled with water. Additional rain will raise the level of the water table. Lack of rain will lower the level of the water table.

Chalk stream: a stream that is mostly fed by water seeping out of the underlying chalk rock. With little run-off water, the water in chalk streams tends to be very clear. They offer a special environment to wildlife, and require protection from pollution and modern developments. There are 210 chalk streams in the world, and 160 of them are in England.

Winterbourne: a seasonal stream fed solely by water, mostly from winter rainfall, seeping out of water-holding rock. Another way of saying this is that the water table rises to a level higher than the stream bed.