The effects of urban growth on

downstream water resources

Mike Hutchins (CEH Wallingford)

Steven Loiselle (Earthwatch Institute)

Steven Loiselle

Community monitoring / citizen science

Lack of field

data for monitoring, earth

observation, model

validation

Active and knowledgeable

communities supporting

improved environmental

management and policies

Why?...

Citizen/Community Science and modelling/monitoring

https://freshwaterwatch.thewaterhub.org

A network of citizen scientists acquiring water quality data in a consistent manner across the globe …

Supporting modelling and management programmes of leading scientists and agencies in 30 locations…

Obtaining robust and consistent water quality and ecological dataExternal and automated quality control

Wat

er c

olou

r

low density

(<14500 org/ml)high density

(>14500 org/ml)

Castilla et al. "Quantification of phytoplankton bloom dynamics by citizen scientists in urban and peri-urban

environments." Environmental monitoring and assessment 187.11 (2015).

Citizen scientist data in catchment scale monitoringHigh phytoplankton densities identified and reported

https://freshwaterwatch.thewaterhub.org/totally-thames-water-blitz

Site specific nitrate concentrations Thames Blitz 16/9/2015

(n= 645)

Citizen scientist data in catchment scale monitoringThames Water Blitz - 645 measurements on 16 September 2015

Challenges of scaleWater BlitzBasin averaged phosphate concentrations

Thames Blitz 16/9/2015 Streams and rivers (n= 620, units = mg/L)

Citizen scientist data in catchment scale monitoringThames Water Blitz - 645 measurements on 16 September 2015

Continuous learning and engagement…creating a virtual community

93% Committed to

personal action

89% Improved

understanding

of water issues

92% Excellent

research

experience

…for the scientist and agency ?

…for the participants?

Hours

CSL sampling

Hours

training

CSLs

Is it worthwhile?...

• Previous modelling work shows that there will be an increase in the number of days per year having undesirable water quality

• Eutrophication is likely to become more prevalent and severe

• This assumes no change in population, which is estimated to increase by 16% to 2035

• We are refining these estimates to consider future urbanisation (in POLLCURB project)

How will water quality change by 2050?

• POLLCURB investigates how water pollution

relates to change in urban areas, in particular

brought about by population growth.

• By measuring land cover, river flow and quality

in urbanising case studies (Bracknell/Swindon),

• and thereby by developing better models of how

change in land cover affects water resources….

• Leads to…. a better understanding of

how urban areas affect our water

resources so we can better plan future

urban developments so they have less

unwanted impacts on these resources

A NERC Changing Water Cycle project…

CEH-led: collaborators…

www.pollcurb.ceh.ac.uk

Increase in urban cover since 1960

Satellite imagery

(5 images since

1975)

Aerial

photography

Topographic

mapping (OS)

Derivation of indices of the percentage of impervious surface cover.

Since 1960, increasing frequency/intensity of storm flows, especially in summer. Without 17 new balancing ponds and flood storage areas changes would have been 20% more severe in Bracknell.

Impact of winter 2013-14 storms in Swindon

Ray at Water Eaton (84 km2)

0

20

40

60

80

100

Pry Great Western

Way

Rodbourne Hayden Wick Water Eaton

Sub-catchments (% urban cover)

1. Transient low DO in sub-catchments a response to pollutant first flushes2. Chronic low DO (and high ammonium) only seen at Water Eaton, not elsewhere 3. Summer DO sags are at least as severe as the winter 2013-14 storms4. Winter DO in 2014-15 at Water Eaton was roughly 2 mg/L higher than winter 2013-14

STW

Sources

In-situ sediment

Runoff: roads and paved areas

Trading estates (poor waste control/storage)

Misconnections in separate storm/foul sewer systems

Sewage and household waste

Contaminated land runoff

Mechanisms Timing

Overflows:• Combined sewers• Storm tanks at sewage treatment works deliver untreated sewage

During/following heavy rainfall

First flushes of accumulated pollutants via surface sewers

Rainfall following dry spells

Treated effluents at sewage treatment works

Continuous: especially important at low flow

Leaky infrastructure Continuous

Diagnosing urban pollution: complex system

Modelling activities for 2050s predictions

QUESTOR model (daily time-step)

CEH weekly water quality (2009 - )Upstream QUESTOR boundary

Tidal limit

Major urban areas outside London

LONDON

20 km

9

65

4

3

2

1

8

7

Cellular automata

land use change

Rainfall-runoffUrban water

management

River channel

water flow/quality

Meta-model

River Thames

water resources

Future climate

Future

urbanisation

upscaling

Local-scale

testing

Basin-scale

application

• A 6-month Follow-on Fund Pathfinder award for a scoping study (End: March 2016)

• 3 workpackages: objectives:

– WP1: enable us to define a business model

– WP2: define sensor technologies and a river monitoring network appropriate for professional scientists, community scientists and stakeholders

– WP3: identify model interface most appropriate for end-users to provide timely information on water quality

• Also a fully-costed proposal for a demonstration study

But the models can also be used for short-term forecasting

A

CEH weekly water quality (2009 - )Upstream QUESTOR boundary

Tidal limit

Major urban areas outside London

LONDON

20 km

9

65

4

3

2

1

8

7

10

WP2: networks to support forecasting between Sites 5-8

• Caversham (5) and Windsor (8) have continuous EA water quality and flow monitoring

• How much better can we forecast if we establish additional monitoring and modelling of the main Thames and its tributary basins (A, B, C)?

• The Cut at Bracknell (C) is a POLLCURB case study

• Catchment based approach (CABA). We are exploring links to EA catchment partnerships in A (Loddon - via University of Reading) and B (South Chilterns - via FWR)

A

B

C

Spectrum

of sensors

Low cost, mobile, ideal for surveys (e.g. depth, temp, cond)

High cost, fixed, ideal for continuous monitoring using e.g. optical sensors

WP3: conceptual design of internet service platform

1. Sensors

2. MobileApplications

3. Data store

4. Analytics and visualisation

For the platform we have

some expertise in CEH. We

are looking for partners with

IT expertise to fully cover

the 4-stage process in the

pilot study funding proposal

Challenges for analytics and visualisation

- Costly to setup the model to run online

- Successfully cater for a variety of information providers and information receivers

Integrate diverse data

from different domains

Maps and charts of (i) data and (ii)

forecast output

“Real time” QUESTOR

model applications

Water quality forecasting is needed!

1. By regulators (e.g. Environment Agency asked for information in June about the likely fate of this year’s algal bloom, a problem ideally suited to our proposed system)

2. By recreational groups (e.g. anglers)

3. We want to investigate the views and potential benefits to the water industry (e.g. protection of water supply intakes?)

1. To act as end-users of the forecasting system

2. To act as advisors in formulating the business model

3. To be facilitators for establishing local networks inclusive of community participation

We are looking for partners for a full proposal

Thank You