Water
Demand for water increases
Below average rainfall in the South East region, coupled with high water demand resulted in Hertfordshire experiencing prolonged drought, a decline in water resources and river habitats. Plans being made for the development of new homes means the county needs to adapt now.
Indicator WR1 - Water consumption
Water consumption in the county remained above the national average of 160 litres per person per day in 2005/06. At 182 litres, this is twice the amount used by our grandparents. The growth of waterconsuming goods like power showers, hot tubs and leisure pools, has contributed to this and it is now essential the trend is reversed to meet future needs.
Hertfordshire domestic water consumption
Source: Three Valleys Water October 2006
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Following the driest period since 1933, Three Valleys Water1 introduced a hosepipe ban in April 2006. The ban prohibited the use of hosepipes and sprinklers to water a private garden or wash private motor vehicles. Three Valleys Water experienced a drop in demand for water by 6% on average rising to 14% in the summer. However, groundwater levels remain below drought trigger levels, the calculations made by Three Valleys Water to implement its Drought Management Plan.
As can be seen from the groundwater graph, levels at Lilley Bottom (one of the observation points to the north of Welwyn Garden City) declined throughout 2005 and continued to fall for the first part of 2006. Rain during the summer halted the decline but was not sufficient to cause a rise. Groundwater levels will continue to deteriorate unless significant rainfall occurs over the winter to recharge them.
Groundwater levels at Lilley Bottom Observation Point in Hertfordshire
Source: Three Valleys Water October 2006
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Three Valleys Water Activities in 2006
- Worked with the county's local authorities to promote water conservation by providing tools and information for websites, literature and events.
- Installed 47,000 water meters, in line with new powers, compared to 21,163 in the previous year. Working towards target of metering 50% of commercial and domestic properties by 2010. Studies show metering reduces consumption by 10 -15%.
- An investment programme was brought forward to cope with the drought's impact; including the upgrading of pumping and treatment facilities and building a new pipeline improving water movement between Hemel Hempstead and Luton.
- Replacement and refurbishment of 640 km of old water mains (many of which are over 70 years old) continued. Begun in 2005, it is part of a £140 million investment plan to reduce the number of bursts and interruptions to water supply.
- Leakage targets for the company were met for the third consecutive year on 14,000 km of water mains. The leakage team was increased by 40% and is expected to repair 5,000 more leaks than the previous year.
Environment Agency abstraction review2
In 2006 the Environment Agency took a strategic look at water resources in all catchments (water supply areas) of England and Wales. The Upper Lee Catchment Abstraction Management Strategy (CAMS), which governs a large part of the county, found water was either over-abstracted, or over-licensed. As too much water is being extracted restrictions may be placed in future on new or renewed abstraction licences and voluntary reductions of quantities will be encouraged.
Indicator WR2 - River Quality
In 2005 the chemical quality of Hertfordshire's rivers deteriorated from 67.2% to 61.2% in the 'very good or good' (A or B) category whilst England and Wales achieved 67.7%. It is a vast improvement on 1998, however, when only 33% of river length achieved 'very good' or 'good' status. In the 'fairly good' or 'fair' quality rating, 31.01% passed, an increase over the previous year's 27.9%. Consequently, a total of 92.21% of its river length is now classed as 'good or fair quality' giving a slight decrease on last year's 95.1%. Whilst 7.8% of river length was classified as 'poor', still no river lengths were classified as 'bad'.
River quality
Source: Environment Agency 2006
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Indicator WR3 - River Quality Objectives
7% of river length in Hertfordshire failed to achieve its River Quality Objectives in 2005, an increase over last year's 5.93%. Most of the failures occurred on stretches of the Grand Union Canal. Its slowrunning nature adds to its water quality problems.
Unlike turbulent, fast-flowing, rivers, it cannot mix pollutants quickly, which would help to absorb oxygen from the air and breakdown organic material. Additionally when nutrient levels are high in a slowmoving river algae growth is stimulated and this can lead to severe oxygen depletion in the water at night. This is common in the rivers and canals of East Anglia and the South East region.
Another factor contributing to the poor water quality reported is hot and dry weather. As rivers have become warmer, the flow, volume and oxygen-carrying capacity is reduced. This impacts on fish and other wildlife, making it harder to breathe and reproduce. Important gravel bed habitats become covered by silt due to low flow and sections of the river dry up. The Water Framework Directive3 replaced the Environment Agency's General Quality Assessment scheme in December and monitors such changes.
Compliance with river quality objectives in 2002 - 2004
Source: Environment Agency 2006
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The impact of household growth proposals RSS14 on water resources in Hertfordshire
The UK government has a policy for over 500,000 homes to be built in the East of England in 2001-21. This is the UK's driest region and the county is expected to provide over 80,000 of these which will have a heavy impact. Already the biggest water consumer in the country, it imports nearly 50% to meet needs that cannot be met by the region.
Through the generation of these new homes demand is conservatively expected to rise by 10% (this excludes the effect of climate change, environmental and land use) and the Environment Agency's Science Group says4 this cannot not be met by new resource development alone. In order to provide sufficient water the county needs until 2030 it states we must:
- Reduce consumption by 25% by fitting watersaving devices in all new properties
- Reduce consumption by 8% by fitting water-saving devices in existing properties
- Increase the use of metering
- Reduce leakage rates
- Develop and implement technology to reuse water; to recycle greywater and harvest rainwater
- Implement water efficiency now to reduce impact
1 See www.3valleys.co.uk
2 See www.environment-agency.gov.uk
3 See Water Framework Directive
4 See East of England Observatory