Under the EU’s Water Framework Directive (WFD), all watercourses in England and Wales must meet strict environmental quality standards by 2027. The adoption of upstream catchment management schemes can prove a more sustainable way of ensuring good-quality drinking water, principally because they combat diffuse pollution at source before it reaches a water treatment works, reducing the need for intensive treatment by chemicals. These schemes can also help companies to contribute towards the requirements of WFD at the lowest customer cost by enabling them to find more cost-effective ways of meeting their environmental obligations.
Wessex Water, which has been active in water catchment initiatives since 2005, knows a thing or two about the benefits available. The company treats and supplies 275 million litres of water a day to 1.3 million customers across the southwest of England, including most of Dorset, Somerset and Wiltshire.
Says Paul Stanfield, head of catchment services at Wessex Water: “We work in two areas of catchment: firstly, upstream of drinking water sources with the aim of ensuring that raw water quality arriving at the treatment works through bore holes or reservoirs is as good as it can be to reduce treatment demands. Also, where we are discharging treated effluent into watercourses, we try to deploy offsetting strategies. In both instances it’s about working with farmers. We don’t have any regulatory powers, so we take a one-to-one engagement approach.”
TRAIN OF THOUGHT
Wessex Water typically imparts a “train of treatment”. The first step is identifying the source of the problem, be it nutrients, farmyard manure or slurries, for example. Is the pollutant running off the fields or seeping from storage? What pathways is it taking to the watercourses or reservoirs? With these questions answered, Stanfield suggests it becomes about implementing as much protection as possible.
“For instance, farmers can obtain grants for slurry storage via the government’s CSF [Catchment Sensitive Farming] programme and other places,” he says. “There are also in-field measures, such as buffer strips, which prove effective at preventing animal waste from entering watercourses. However, the cheapest and most widely used measure is cover crops. Rather than leaving bare soil over winter, which leads to increased run-off and leaching, the planting of a nominal crop, not necessarily for harvesting, will use up any leftover nitrates and prevent issues from developing.”
Stanfield rightly points out that water catchment management does not provide 100% security, which is a major challenge, particularly regarding drinking water quality standards.
“You only need one pesticide exceedance for it to become a problem,” he states. “With this in mind, our approach lies in understanding the problem holistically, beyond just phosphorous or nitrates. Carbon, for instance, is a big issue. If we build a treatment works to remove nitrate, that’s all it does, nothing more. In addition, the treatment process relies on many chemicals and their associated transportation. By taking a catchment approach you get wider benefits, such as flood reduction, biodiversity improvements, pollination and so on. We’re not saying we won’t need to build any more treatment works, we’re just looking at more holistic, sustainable solutions where possible.”
RISING COSTS
One of the challenges that could slow the uptake of water catchment schemes is cost, largely due to competition from housing developers regarding the assurance of nutrient (phosphorous and nitrate) neutrality. As a result, the demand for nutrient offsets has soared. Both water companies and housing developers are looking to buy offsets from farmers, so the price inflates.
“While we expect catchment management costs to rise moving forward, it remains orders of magnitude cheaper than building and operating treatment works,” says Stanfield, who views Wessex Water as punching above its weight in water catchment. “We’re pushing the agenda by setting up catchment markets that bring buyers and sellers together. We’re also looking at working with Ofwat to develop different ways of delivering plans in line with WINEP [Water Industry National Environment Programme], aside from the traditional building of treatment works.”
The thinking is similar further north at United Utilities, which covers the entire of northwest England, from Cumbria, down through Lancashire, Greater Manchester and Merseyside, to most of Cheshire and a small part of Derbyshire. The company began its first water catchment initiative in 2005, via its Sustainable Catchment Management Programme (SCaMP).
“SCaMP focused primarily on the improvement of raw water quality, tying in with really strong gains in biodiversity,” explains Jim Airton, natural capital strategy and planning manager at United Utilities. “About 46,000 hectares of our area is catchment land to safeguard the protection of our water resources. We looked at how we could invest in and manage that land to drive better water quality provision into our reservoirs and our clean water treatment works, making the process more cost effective.”
Airton says that water catchment initiatives bring many advantages. Take peatland restoration involving the rewetting of soils, for example. This activity ensures more effective retention of water in the head waters, so it drains far more slowly through the land for better filtration and flood management. Additionally, it does not drag organic material with it because the water is flowing much slower.
By 2015, United Utilities began thinking about a new phase, involving a more holistic and integrated approach. Part of the focus nturned to wastewater operations and the discharge of treated effluent into rivers.
“There are many challenges here, such as compliance with WFD, which encompasses not just wastewater issues, but agriculture, how we use our land, urban drainage and so on,” explains Airton. “All form part of a holistic approach to river protection. By tackling all of these we can reduce the scale of treatment required, using reactive media that works in a more passive way than intensive chemical treatment. It also drives down greenhouse gas emissions through enhanced land management and delivers better flood management.”
CAST FORWARD
This thinking evolved into what United Utilities now calls its CAST (Catchment Systems Thinking) approach.
“CAST drives an integrated strategy into our own delivery and what we need from catchments, along with how we can work with partners to understand what they need. In short, it’s a wholesale catchment approach: the right intervention in the right place, with the right partners, striking a balance between what’s best for the environment, our customers and communities. It’s not to say we won’t be investing in grey infrastructure and hard engineering, as that’s absolutely what we need in some instances, but we now have a portfolio of nature-based solutions at our disposal that offer a broader range of benefits.”
Ultimately, the company wants to continue managing water in a holistic manner to fully understand the impact of its activities on the environment. CAST encourages United Utilities to think differently by integrating risks, driving multiple natural capital benefits, and developing better ways of working through co-governance, collaboration and partnerships.
As a final point, climate change is of course impacting all elements of the water industry, where the challenge is driving effective investment to level up drier summers and wetter winters. Catchment management has a really important role to play.
“Holding greater water levels within the landscape provides longevity in low rainfall periods,” concludes Airton. “And, when we get higher levels of rain, it can provide greater capacity in the land to hold the flow back. It’s all about understanding the mechanisms to drive ecosystem resilience.”