Transcript Water Supply in Hampshire - Vitacress Conservation Trust

Hampshire Chalk Stream
Headwaters Forum
Southern Water
Water Supply in Hampshire
 Background of the water supply
 Where does the water come from ?
 How much is abstracted ?
 Planning for the future
 Challenges
Southern Water’s Resource Zones
• Supply water to 9
distinct areas in
the South East
•Currently supply
water to 2.28 M
customers, set to
increase to 2.61M
by 2025.
Hampshire Andover
Kent Medway
Hampshire Kingsclere
Sussex North
Kent Thanet
Sussex East
Sussex Coast
Hampshire South
Isle Of Wight
•70% of the water we abstract comes from the Groundwater; 23%
from rivers and 7% from reservoirs.
•Current average daily demand is 595 Ml/d and this will increase to
661 Ml/d by 2025.
•Collect and treat the effluent for all of the area
Southern Water’s Hants Resource zones
Southern Water’s Sources & key internal transfers
Sources
 Abstraction from 18 sources
 Largest abstractions in the lower
reaches of the Test and Itchen
catchments
 9% of the total abstraction in
Hants occurs in Andover zone
 3% of the total abstraction in
Hants occurs in Kingsclere zone
 89% of the total abstraction in
Hants occurs in the South zone
 Large scale abstraction in Hants
date back to the late 1890’s
Source usage North Hants
Average use (Ml/d)
Source
Andover
Chilbolton
Faberstown
Ibthorpe
Overton
Whitchurch
Total
Licence Limit
(Ml/d)
16.02
0.50
0.82
5.71
1.64
1.64
26.33
2002
11.72
0.19
0.00
2.35
0.76
0.66
15.69
2003
11.95
0.24
0.00
2.58
0.96
0.83
16.57
2004
12.17
0.30
0.00
3.05
1.05
0.81
17.38
2005
11.69
0.25
0.00
2.84
0.93
0.84
16.55
2006
11.28
0.20
0.00
2.49
0.89
0.88
15.74
2007
11.21
0.21
0.00
2.31
0.64
0.85
15.21
61%
Average use (Ml/d)
Source
Kingsclere
East Woodhay
Total
Licence Limit
(Ml/d)
5.70
3.00
8.70
2002
2003
2004
2005
2006
2007
3.45
1.04
4.49
4.06
1.23
5.30
4.04
1.21
5.25
3.94
1.28
5.22
3.69
1.16
4.85
4.19
1.02
5.21
58%
Current Usage South Hants
Average use (Ml/d)
Source
Licence Limit
(Ml/d)
2002
2003
2004
2005
2006
2007
1.12
0.91
0.99
0.85
0.98
0.92
0.93
18.18
16.98
12.14
9.89
13.35
11.61
12.98
5.00
1.59
1.55
1.60
1.57
1.52
1.49
13.68
3.94
5.32
5.10
5.66
5.24
5.27
Totford
4.55
2.83
2.80
2.78
2.93
2.91
3.24
Tywford
36.49
19.43
20.73
19.73
14.62
16.04
18.13
54.79
45.58
136.75
316.15
42.66
25.29
62.21
175.83
41.10
26.78
58.12
169.54
41.66
22.89
61.48
166.00
43.29
23.15
62.03
167.59
43.59
22.43
56.23
160.49
44.44
15.70
62.63
164.83
Barton Stacy
Easton
Horsebridge
Timsbury
Otterbourne GW
Otterbourne SW
Testwood
Total
53%
Demands
 Demands steadily grew from 1976 to 1989 when they
peaked
 Since this time demand in Hampshire has been steadily
falling
 Typically due to leakage reduction, metering and water
efficiency
 More recently demand fell due to restrictions in
neighbouring areas
 Populations in each of the zones are:
– Hants Kingsclere zone ~ 16k
– Hants Andover zone ~ 65k
– Hants South ~ 610k
Demands
Average daily DI
Hosepipe ban introduced
200
180
140
Data
Average of IOW
Average of Hants
Average of North
Average of Coast
Average of East
Average of Medway
Average of Thanet
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10
11
12
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2
3
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9
10
11
12
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2
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10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
Distribution Input (Ml/d)
160
2002
2003
2004
Year & Month
Year Month
2005
2006
2007
How do we use the water
Water use in the home
In the kitchen
15%
Dishwasher
1%
Wash basin
9% Outside use
4%
Bath
15%
Clothes washing
20%
Shower
5%
Flushing the toilet
31%
Typical demands during non-summer months
Demands during the summer - weekdays
Consumption pattern during the War
Planning for the future
 Water resource plans are now statutory and will go out to
consultation next year
 Since 1989 plans submitted on a voluntary basis
 Plan to meet the demands in 25 years time
 Since 1997 Water Resources in the South East of England
technical group was formed
 Assisted with two Water resource plan submissions
 Participants include the EA (Chair), DEFRA, OFWAT, EN,
SEERA, Portsmouth, South East Water, Mid Kent,
Folkestone and Dover and Southern Water
 Integrated water resource plans across all companies
Water resource planning in the South East
 Plans look at a twin track approach
 Use existing stocks of water more efficiently
 Develop bulk supplies, where appropriate
 Develop new resources, major resources are
shared
 Informed SEERA of infrastructure requirements,
written into their development plans
Supply-demand balance
demand +
headroom
demand
Ml/d
deficit
deficit
demand
demand
+
headroom
supply
surplus
Time
Demand side options
 Metering policies
– Optants, change of occupier & compulsory
– Consumption habits & micro component analysis
 Leakage reduction
– Dominated activity since mid 90’s
– Currently operating 10 Ml/d below our target level
set by OFWAT
 Water Efficiency
– devices, voluntary codes and behaviour...
Supply options
 No groundwater options, ASR remains the last
area to explore
 Winter water: reservoirs or resting groundwater
 Desalination
 Effluent re-use
 Bulk transfers, both local and national level
 Conjunctive use of surface and goundwater
Challenges for the Region
 High growth
 Sustainability reductions (Habitats directive,
Ramsar, SSSI)
 Water Framework Directive
 Deteriorating groundwater quality
– Diffuse: nitrate and pesticide
– Point source pollution
 Climate Change
Deteriorating Water quality in groundwater
Climate change – Modelled Change in Groundwater Level (HADCM3 vs
Baseline)
Key
5 Difference in modelled
4.5 groundwater level:
4 Scenario - Baseline (m)
3.5
3
2.5
2
1.5
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
-4
-4.5
-5
170000
165000
160000
155000
River
Boundary of Chalk outcrop
150000
Test and Itchen
groundwater catchment
145000
140000
135000
River Itchen
130000
125000
120000
115000
15000 m
0m
Scale 1:300,000 @ A3
CL/04/Groundwater Task
GR3 Method in the River Test Catchment
110000
400000
405000
410000
415000
420000
425000
430000
435000
440000
445000
450000
455000
460000
465000
470000
475000
480000
485000
490000
Comparison of Modelled Heads in Chalk
Period of Dry Late Summer
(Nov-2024, equivalent to Nov-1989)
HadCM3 minus No Climate Change
September 2006
mincw
Monthly Flow Factors for 2020s - Hants
Itchen@AllbrookHighbridge (42010)
50
90% confidence intervals
50% confidence intervals
median
Change in monthly recharge (%)
40
30
20
10
0
-10
-20
-30
-40
-50
J
F
M
A
M
J
J
A
S
O
N
D
What’s in the future ?

Ensure customers understand what they are using through metering

Help the existing and future housing stock become more water efficient

However, in a 2 or 3 year drought using less water helps but without storage
then water that not is taken today will not be there tomorrow.

Move away from single source dominant supply areas, particularly river, to
ensure the systems can capture the water when it is appropriate to do so.
Different combinations of sources will improve the robustness of a zone

Look to solutions that will make the most of the opportunities afforded by climate
change e.g. winter water.

Ideally plan around schemes whose output are less sensitive to droughts.
Drawback is that these use more power

Look for low energy solutions which require less pumping or minimal treatment

Future selection of solutions will take account of carbon footprint, both during
construction and operation
What else ?
 Focus on catchment integrated solutions rather
than just end of pipe solutions
 Regulations that encourage global solutions
 Technology:
– R&D,
– full scale trials on innovative solutions,
– National studies