Cardiff Bay - Environmental Management

and Implications for Recreational Use

David Hall

Cardiff Harbour Authority

Post War Decline

• Major impact on South Cardiff

• Move to oil

• Containers and efficiency of larger ports

• Closure of East Moors steelworks

• High rates of unemployment

• Reduction in land values

Regenerating Cardiff Bay

• Commenced in 80’s with move of County Hall

to Cardiff Bay

• Development Corporation set up in 1987 to

regenerate the 1,100 hectares of derelict

docklands

• £500m public sector investment 1987 to 2000

• Main Infrastructure projects were Cardiff

Barrage, Butetown Tunnel, PDR.

CBDC Achievements

• The construction of the Cardiff Barrage

• 31,000 new jobs

• 6,000 new housing units

• 327 hectares of land reclamation

• 695,000 sq metres of commercial

developments

• £1.7billion private sector investment

CBDC Achievements

• The construction of the Cardiff Barrage

• 31,000 new jobs

• 6,000 new housing units

• 327 ha of land reclamation

• 695,000m2 of commercial developments

• £1.7billion private sector investment

Pre Barrage Concerns

• Debris management

• Flood defence

• Migratory fish

• Dissolved oxygen levels

• Water quality

• Algae

• Birds

• Pests (rodents and chironomids)

• Groundwater levels

Pre Barrage Concerns

• Debris management

• Flood defence

• Migratory fish

• Dissolved oxygen levels

• Water quality

• Algae

• Birds

• Pests (rodents and chironomids)

• Groundwater levels

The Ely & Taff catchments

Debris Management

• > 95% of debris originates from outside Harbour

Authority jurisdiction

• Prior to Barrage, debris eventually washed out into

Severn Estuary

• Debris now contained within Bay

• Two pronged attack – land and water

• In 2013-14, 600 tonnes of debris removed from the Bay

• Of this, 50 tonnes of wood were segregated for fuel use

Cardiff Bay Barrage Act 1993

– Cl. 8 (1)(a) – protect the quality of the water

in the inland bay by ensuring that it meets or

continues to meet the relevant standard

– Cl. 8(2) – quality of water meets this

standard if it contains not less than 5mg/l

dissolved oxygen at all times

Dissolved oxygen levels

Sewage pumping station discharge

Non-compliance due to sewage

discharge

Aeration system cross section

Graph – benefit of aeration system

C o mpariso n between to p and bo tto m disso lved o xygen (8 metres depth)

5

7

9

11

13

15

23-Jun 24-Jun 25-Jun 26-Jun 27-Jun 28-Jun 29-Jun 30-Jun 1-Jul

D.O

. (m

g/L

)

1m from surface 1m from bottom

Large gradient develops

Aeration ON

Oxygen gradient reduces

Oxygenation Barge

Water Quality

• All activities are based on a Risk Assessment approach

• Decisions based on a predictive model

• Health monitoring is carried our for all participants

• Every case of illness followed up and investigated

• Process in place was developed in conjunction with

Public Health Wales

Water Quality Model

Classification

Faecal

coliforms

(per 100ml)

Streptococci

(per 100ml)

EC Bathing

Waters

classification

EXCELLENT

<100

<100

Guideline

GOOD

100 to 2000

N/A

Imperative

POOR

>2000

>100

Fail

Water Quality

Use of Water Quality Model

• Run model on daily basis

• Provide information to public to facilitate

informed choice

• Provide an input into management of water

sports centres

• Facilitate day to day programming of activities at

water sports centre

Use of Water Quality Model

Algae

• Monitored weekly in the autumn and winter

• Monitored twice weekly in spring and summer

• Samples analysed using algal analysers (both lab

based and algal torch)

• Alert Level Framework in place in the event of Blue

Green algal blooms

• No significant blooms within Cardiff Bay since

impoundment

Algal scums

Pests

• Chironomids

• Rodents

• Invasive species

• Zebra Mussels

• Killer shrimp

Pests

Water based events • Home Nations Rowing Regatta

• European Water Ski Championships

• Formula 3 and Formula 500 Powerboat World

Championships

• ICF Canoe Slalom World Cup

• RYA National Powerboat Championships

• Extreme Sailing Series

• Triathlons

• Volvo Ocean Race (2017)

Cardiff International White Water