Good water quality

Overall vulnerability

Feature assessed:

• Good water quality (Water Framework Directive)

Special qualities:

• Vital benefits for millions of people that flow beyond the landscape boundary

Feature description:

The Water Framework Directive (WFD) aims for surface and ground waters to be of ‘good’ status. This status is assessed according to various factors such as the biological, hydromorphological, physical-chemical and chemical qualities of the water system.

The PDNP has approximately 400 km of surface water systems that fall within the WFD. These include rivers, lakes and reservoirs; and can be rated as high, good, moderate, poor, or bad. A moderately productive aquifer underlies much of the PDNP, with many springs. Similar to surface water, these are rated under the WFD as good or poor. The impact of climate change on this ground water is assumed to be lower than for surface water as it is naturally filtered by rock up to 900 mm thick.

While the focus of this feature is mainly surface water, similar climate impacts are expected for groundwater.

How vulnerable is good water quality?

Good water quality in the PDNP has been rated ‘high’ on our vulnerability scale. This score is due to high sensitivity and exposure to climate change variables, coupled with a moderate current condition, and a moderate adaptive capacity.

Increased sedimentation and nutrient leaching may negatively affect water quality in the future. Furthermore, increased nutrient availability coupled with increased erosion and disturbance may facilitate increases in non-native invasive species. Good water quality in the PDNP has been attributed a moderate adaptive capacity. This is due to strong legislation and regulatory processes being in place and the potential for catchment wide management policies to positively impact water quality.

Current condition:

The poor condition of blanket bogs within the Dark Peak has led to high levels of water contamination, especially of dissolved organic carbon during high flow events. The Derwent Reservoir catchment is one such example, with high levels of dissolved carbon and colour in the reservoirs. Severn Trent water are trying to combat this by funding moorland restoration works on the surrounding hills. Further downstream, pesticides, herbicides and phosphates are issues in places such as the Tittesworth Reservoir catchment and the Wye catchment. Agriculture is a significant employer in the PDNP, with the 2,555 agricultural holdings giving an indication of scale of managed land.

PDNP watercourses are host to several non-native species, including signal crayfish, American mink, Himalayan balsam, Japanese knotweed and giant hogweed. These species affect water ecosystems and therefore good water quality as defined by the WFD. Transfer of water between waterbodies poses a risk of spreading such invasive species. Of the water bodies included in WFD assessment, approximately 40% are good quality, 60% moderate and 2% poor. This implies that water quality in the PDNP is generally reasonable, but has room for improvement. The majority of PDNP watercourses are too small for inclusion in the WFD, and so have not been assessed.

Groundwater bodies are generally rated as good, however the chemical status for some is poor (for example, the Derwent Carboniferous Limestone and the Derwent Secondary Combined catchments) due to mining and quarrying activity. Management of these groundwater bodies falls within the greater Humber River Basin catchment.

What are the potential impacts of climate change?

Overall potential impact rating

Nutrient changes or environmental contamination Drier summers increase the risk of eutrophication, affecting both humans and animals. Associated with this is an increased risk of algal blooms, which can reduce drinking water quality. Due to these changes, water treatment requirements may require modification. Extended periods of dry weather may cause drying deep within peatlands of the Dark and South West Peak. Sudden increases in flow may then result in acid pulses through watercourses, potentially negatively affecting wildlife and the general trend for recovery from acidification. Data Certainty: High

Increased annual average temperature may cause nitrogen flux due to soil decomposition resulting in increased nitrogen concentration in watercourses. Furthermore, pockets of anoxia may increase caused by greater biological oxygen demand. Data Certainty: High Increased levels of nitrogen from atmospheric pollution may also lead to greater rates of growth of pond vegetation. Furthermore, many species associated with rivers and lakes are sensitive to changes in water chemistry. Data Certainty: Moderate

More frequent and intense storm events may result in spikes of nutrient contamination in watercourses due to fertiliser wash off and discharge from storm drains. Data Certainty: Moderate

Sedimentation or erosion

Wetter winter and drier summers may lead to the silting of reservoirs, both reducing water storage capacity and adversely affecting water quality. Data Certainty: High Hotter summers may increase the likelihood sedimentation by increasing the chance of wildfires in plantations surrounding reservoirs. Data Certainty: High An increase in intense storm events would compound sedimentation issues, increasing the quantity of fine sediment entering watercourses. Data Certainty: Moderate The speed at which river erosion processes such as bank collapse occur is likely to increase as extreme storm events become more frequent. Data Certainty: Moderate

Human behaviour change

Frequent droughts and floods, coupled with generally warmer temperatures may result in land use change - as current practices become unsuitable or new practices become possible in some areas. This could lead to pastureland being converted for arable use, new crops being grown and increases in the uses of pesticides, potentially affecting water quality. Data Certainty: Moderate

Hydroelectric energy schemes may become more prevalent as a climate change mitigation measure. Such schemes may require water to be diverted or current channels modified to house hydroelectric equipment, negatively affecting water quality as defined by the WFD. Data Certainty: Low

Hotter summers could result in an increase in water bodies being used for recreation, increasing the risk of pollution from litter and boat fuel for example, causing water quality to deteriorate. Data Certainty: Low

Invasive or other species interactions

Increased nutrient availability could result in increased plant growth rates. Water quality could be reduced in areas colonised by invasive species. Data Certainty: Moderate Increased annual average temperature may mean invasive marginal water plants are able to become more prevalent. If these plants then die back during the winter, banks may be exposed to increased erosion - reducing water quality. Data Certainty: Low More regular intense storm events could also increase erosion of riverbanks, providing greater opportunity for invasive species to colonise, reducing ecological condition of watercourses. Data Certainty: Low

Direct impacts of climate change

Increased annual average temperatures would result in more rapid mineralisation of organic matter and increased macrophyte growth in water bodies, therefore increasing evapotranspiration. Water quality may be reduced as these biological changes occur. Data Certainty: High An increased water temperature coupled with periods of low water due to drought are likely to harm the biological status of waterbodies. Species adapted to cool water and fast currents such as Salmonids are at risk of loss or range contraction if suitable climate space moves upstream. In addition, shifts in phenology of aquatic invertebrates are likely to change the abundance of species through the disturbance of established food webs. Data Certainty: Moderate

What is the adaptive capacity of good water quality?

Overall adaptive capacity rating

The huge improvements in water quality that have been made in the UK indicate that future recovery from damage is possible if human behaviour changes. However, it should be remembered that only a small percentage of rivers in England and Wales are currently considered pristine. Data Certainty: High Rivers with modified banks and flood protection structures will be less resilient as they have lower potential to re-naturalise, and nationally these modifications are often the reason that rivers fail to meet WFD good status. Data Certainty: Moderate Some cold-water species may however be lost and unable to recover. Data Certainty: High

Upstream management plays a role in water quality. Improved land management in the PDNP, for example blanket bog restoration, clough woodland establishment and environmentally sensitive farming practices at a landscape scale, have good potential to improve water quality despite climate effects. Data Certainty: Very High The PDNP also has a wide range of waterbody types with different characteristics, due to the diverse geology and topography of the area. This diversity increases the adaptive capacity of the water resource as a whole. Data Certainty: High

There is strong legislation and regulation for monitoring and enforcement of water quality through the WFD. However, the Environment Agency only monitors ‘main rivers’ meaning smaller streams and rivers - where climate effects may be felt more strongly - may be at greater risk. Water companies have processes in place for triggering drought protocols to manage water levels. Data Certainty: High

Agri-environment funding is currently available for habitat works that could help improve water quality at the catchment level, but complexity of schemes can reduce the incentive for landowners to take part. Changes in funding strategies towards a ‘payment by results’ approach may increase uptake in the future. Some water-related funding sources may be available such as those directed at Flood Risk Management or funding aligned to water industry drivers. However, there is currently much uncertainty surrounding the future shape of this type of funding. Data Certainty: High

Key adaptation recommendations for good water quality:

##Improve current condition to increase resilience The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are aimed at improving the condition of the feature at present, therefore making it better able to withstand future changes to climate.

• Carefully manage water usage, especially during the summer.
• Establishment of riparian areas to maximise vegetation cover can help to reduce nutrient and sediment load entering watercourses.
• Restoration of soils can help to improve infiltration rates and reduce run-off and the risk of erosion.
• Buffer strips to trap sediment before it reaches a watercourse should be established wherever possible.
• Continue moorland restoration work to improve water quality.
• Restoration of natural processes across the catchment will improve watercourse health and therefore resilience to change.
• Minimise agricultural inputs, especially fertilisers and pesticides. Give consideration to good management of waste to improve catchment quality, including effective slurry store management.
• Restoration of healthy soils in river catchments will increase infiltration of water and reduce runoff, thereby reducing sedimentation. Tree establishment is a known method to improve infiltration and reduce pollutant spread from runoff.
• Restoration of semi-natural vegetation on critical runoff pathways will slow the flow and reduce erosion.
• New hydroelectric power developments should not be allowed to prevent restoration of natural processes in river systems.
• Use of low nutrient livestock feeds will reduce contamination of the watercourse.
• Evaluate whether the introduction of beavers would be a feasible and appropriate method of delivering ecosystem service benefits such as flood mitigation, water quality and wet woodland creation.