Our challenges

The challenges we face

Whilst the Upper Aire catchment envelops a myriad of priority habitats and is characterised by several environmental and site designations, fundamental issues exist which pose a significant threat to associated habitat, wildlife and environmental quality.

Challenge one

Water Quality

Water quality is determined using the EU Water Framework Directive classifications. In the Upper Aire, surveying has been conducted to determine the reasons for not achieving 'good' status on classifications. Causes of poor status have been identified and attributed principally to agriculture and rural land management, typically manifesting through pollution from rural areas (slurry, fertilisers, pesticides and sediment) and physical modifications within the catchment.

The water industry, associated with wastewater pollution, has also been documented as contributing to poor status. River reaches with low water quality are unable to support wide ranges of species, which in turn reduces overall biodiversity of riparian and aquatic habitats. Sediment pollution in waterways can also pose a threat to population growth of fish species through a reduction in availability of desirable breeding grounds.

Challenge two


Flooding along the Aire may be exacerbated by mismanagement of the landscape which has previously encouraged draining of peatlands, straightening of river channels and heavy stock grazing causing ground compaction and erosion. Livestock grazing remains the predominant land use in the Upper Aire, rendering only 5% tree canopy cover across the catchment.

This low canopy cover further reduces ability to hold back and store water in the catchment and increases the chance of runoff processes. Sediment pollution in channels can also increase flood risk due to a decrease in the channel capacity of the river which encourages above bank flow during rainfall events. The combination of these factors has led the river to quickly 'flash' (water levels to rise rapidly) during periods of rainfall and increased the risk of flooding both locally and downstream.

Within the Upper Aire flooding has affected properties and businesses in Earby and Gargrave, while downstream larger communities in the Mid and Lower Aire including Bingley and Leeds have been subject to flooding.

This was most severely felt during the Boxing Day floods 2015, which affected up to 5000 properties in Leeds and the river rose to a record-breaking 5.22m at Armley. This flood was a 1 in 200 years+ event, however with weather patterns resulting from climate change become increasingly erratic, extreme events such as the 2015 floods are likely to become more frequent across the Upper Aire catchment as well as downstream.

Challenge three

Threats to Habitat and Biodiversity

Livestock overgrazing

The intensification of land management through livestock overgrazing has caused erosion, poaching and ground compaction which cumulatively exacerbate flood risk along the Upper Aire. Greater numbers of livestock across the catchment have also reduced the habitat availability for many species, including those already threatened by biotic and abiotic factors. This includes notable bird species such as skylark, curlew, redshank and lapwing who nest in grazing land but have suffered from increased risk of trampling of nests; short sward length resulting from current land management practices offer nests little protection.

Overgrazing also reduces the likelihood of establishment of a biodiverse sward. Fresh green shoots are quickly grazed by livestock, which in turn reduces the diversity of invertebrates and thereby creates communities dominated by few hardy grass species.

Channel modifications

Channel modifications have a significant impact upon the wildlife and quality of waterways. Channel morphology alterations made through realignment, rock armouring banks and channelisation can cause significant ecological damage both within the channel and across the banks and riparian zone. Loss of biodiversity because of these modifications can be found within the Upper Aire catchment.

Similarly, the impoundment of water characterised by weirs poses a large threat to ecosystem health. The presence of weirs encourages a shift in the natural hydrological regime associated with upland channels; weirs encourage over deepening of reaches above the feature and increased erosion downstream. As a result, aquatic habitat and species diversity can decline.

With increased sediment deposition above the weir, fish spawning grounds can be smothered and the channels capacity is reduced. Moreover, weirs can inhibit fish migration and movement both in upstream and downstream locations, creating isolated populations which become inherently more vulnerable to additional environmental issues such as pollution.

Invasive species

Invasive non-native species (INNS) such as Himalayan balsam can reduce the diversity of species found alongside riverbanks in the riparian zone. Presence of these INNS can also reduce bank stability. During winter, substantial die-back can leave banks exposed to erosion and may result in a reduction in water quality from excessive sediment input. In addition, invasive Signal crayfish (Pacifastacus leniusculus) also threaten biodiversity in the Upper Aire. Substantial losses to the abundance and populations of native white-clawed crayfish (Austropotamobius pallipes) have been observed, resulting from crayfish plague, competition and predation, exacerbated by the presence of INNS.

The introduction of invasive species results from human intervention and mismanagement of landscapes, and therefore work to manage this threat is necessary to resolve this imbalance. Monitoring for invasive species, stringent biosecurity and action days can all help manage this threat in the Upper Aire catchment. For information on INNS and to see how you can help, please visit get involved. For more information on the threat of invasive species and how to ensure you promote and carry out suitable biosecurity while enjoying the Upper Aire please visit the Yorkshire Invasive Species Forum.


What can be done to address the challenges?

Natural flood management (NFM), defined as measures which work with natural hydrological and morphological processes, features and characteristics to manage the sources and pathways of flood waters, offer a pragmatic solution to managing flood risk. Customarily involving alteration, enhancement and restoration of natural features to store flood water and slow respective flows, the timing and magnitude of flood peaks downstream may be attenuated through adoption of NFM techniques.
Additionally, such practices are typically cheaper and more sustainable than the majority of existing hard engineering approaches, the latter of which are often considered undesirable. This further necessitates the urgency to employ NFM as part of effective catchment flood risk and environmental management strategies in the Upper Aire.

Measures to reduce flood risk, improve water quality and habitat and biodiversity:

Walkover surveys

Surveying the River Aire can identify issues and areas of key concern and highlight locations where opportunities for environmental improvement works can occur; advice on remediation work can be given to landowners within these targeted areas.

Buffer strips

Buffer strips are areas of uncultivated/un-grazed land alongside rivers or in fields, planted with trees, shrubs, and grasses.

Drinking points

Excluding access for livestock to channels is encouraged to reduce erosion and poaching of banks. Alternative water supplies can be investigated to allow soil water storage to improve and for ecosystems to recover. Installing drinking points for livestock instead of allowing them to trample banks and access the river are considered for instances where alternative drinking sources are not available.

Leaky woody debris dams

A leaky dam is a structure built from logs or branches installed across a ditch or small watercourse. They are built in the upper reaches of a river above the normal flow rate (base flow) and are designed to mimic trees that fall across river and store water. Alternatively in well vegetated and wooded areas, trees can be felled and laid across a channel to represent a more natural system.


Plant hedges across fields, along field boundaries or perpendicular to overland flow paths.

Riparian fencing

Installing fencing alongside riverbanks prevents livestock from accessing rivers.

Soil aeration

Soil compaction can occur on land where there are high stocking densities or where heavy machinery is regularly used. Soil aeration aims to reduce compaction and overland flow by increasing soil health and the soils’ ability to hold water.

Tree planting

Planting native trees and creating new woodlands.

Wetland Scrapes

Scrapes, or shallow ponds, are areas designed to act as a temporary water storage pond during periods of high rainfall.

Weir removal/adjustment

References & further reading