'97 Update

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Water

Introduction

1997 was another relatively dry year, and low rainfall has added to the ongoing concerns regarding water resources in Hertfordshire. In 1996/97, we demanded 311 million litres per day on average, rising to a peak demand of 390 million litres per day during the summer period.

Indicator 1: Water Consumption

Due to a change in the calculation methods for water consumption the figure is not comparable with that for last year. However, it is thought to be more representative of personal water use. The 1997 figure is:

· Household Per Capita Consumption - 172 litres per person per day.

This figure represents a 3% fall in consumption from 1995/96 according to environment agency records and is attributed to a reflection of the difference in weather patterns. This figure was not available last year.

Water Companies no longer use percentages to show the level of water leakage from supply pipes, prefering to show leakage in quantity terms.

Indicator 2: River Quality: General Quality Assessment

The Environment Agency monitors the quality of our rivers in two ways. The first is called the General Quality Assessment (GQA) and is used to make regular assessments of the river quality, to monitor trends over time and to compare rivers in different areas. This scheme classifies rivers from 'A' (very good quality) to 'F' (bad). 311.76 km of river has been monitored and the results show that Hertfordshire has:

175.38 km of class A or B (good quality) and

16.71 km class E (poor) rivers, out of a total of 311.76 km.

The total length of class A or B rivers has fallen from 58% to 57% of the total and class E rivers has increased from 4.8% to 5.35%.since 1996. This reduction in river quality has been put down to the infrequent rainfall in 1997 resulting in low flows in rivers. Underground water has not been replenished because of low rainfall, further lowering river levels. Constant, steady rain over a sustantial period is required to raise river and water table levels.

Indicator 3: River Quality Objectives

The Water Quality Objectives in the 1996 Update Report are now referred to as River Quality Objectives (RQOs). These objectives uses a system which grades

what plants, animals, and insects exist within the river and what chemicals make up the water itself. When the river has been graded between 1-5 on the River Ecosystem, the environment agency set an objective to either maintain or improve the existing quality of the river.

• This year 271.43 km of rivers have had RQOs set and all have passed.
• The remaining 40.43 km of rivers in Hertfordshire will have objectives set by the year 2006.
• This compares to 88 km having water quality objectives set and all reaching their targets in 1996.

Map of River Class Survey

For further information contact: John Mills at the Environment Agency. Tel: (01707) 632300.