International Conference on Peri-Urban Landscapes: Water, Food and Environmental Security, Sydney, Australia, July 8-10, 2014. Adjunct Associate Professor Bruce Simmons Presentation

1. DEVELOPMENT OF FUTURE
MANAGEMENT OPTIONS FOR THE
HAWKESBURY RIVER
Associate Professor Bruce Simmons,
Dr Uthpala Pinto, Dr Jennifer Scott
and Professor Basant Maheshwari
University of Western Sydney, NSW, Australia,
Ku-ring-gai Council, Sydney, NSW, Australia.
1

2. The Hawkesbury River Story
A history of development, impact and response.
Development
River
Impacts
Community
Concerns
Community
Responses
Outcomes
Evaluation

3. Sydney’s Population Growth
(based on Flood 2003 and ABS 2013)
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
1750 1800 1850 1900 1950 2000 2050 2100
P
o
p
u
l
a
t
i
o
n
Year

4. Development and River Impacts.

5. The Hawkesbury River – Development Patterns
Time Flow Development Activity
1793-
50
Flood
till 1820
drought
Early European
Settlement
Food Production,
River Transport,
Macquarie Towns
1850-
1900
Flood Opening up of
Catchment
Road, Rail, Clearing,
Farming, Grazing
1900-
1950
Drought Water Supply Dam Building,
Irrigation
1950-
1990
Flood Growth of
Sydney
Instream Aggregate
Extraction
1990- Drought Expansion of
Sydney
Urbanisation

6. The first 22 farms on the Hawkesbury River, 1794
(in Barkley & Nichols, 1994, attributed to University of Sydney Cartography).

7. The Settlement on Green Hills, Hawkesbury
River, NSW 1809
(watercolour attributed to George William Evans. Original held at State Library of NSW)

8. Land Clearing
(Pictorial History Hawkesbury Publ.)

9. The Purple Noon’s Transparent Might
(a painting of Freemans Reach by Arthur Streeton 1896. Original held by the National
Gallery of Victoria

10. Dam Building 1900-1960 Warragamba Dam
Sydney Morning Herald February 10, 2008. photo: Anthony Johnson.
www.smh.com.au/.../2008/02/09/1202234227091.html

11. Dredging
Mean depth of the Hawkesbury River (SPCC 1984)

12. Riverbank collapse at North Richmond 1967
(photo RAAF Richmond, in Barkley & Nichols 1994)

13. River Bank Collapse at Windsor
Councillor Ted Books WISER Community Consultation Presentation 2007

14. Nutrient Pollution. Ortho-phosphorus concentrations
Hawkesbury River in the 1940s and 1979–81 (SPCC 1983)

15. Blue-green algal bloom at Windsor (SPCC 1984)

16. Egeria densa beds in the Nepean River (photo
Simmons 1996)

17. Responses of the Hawkesbury River to Human
Activity
Time Activity Response Indicators
1893-
1850
Farming,
River trade
Bank erosion Navigation
Bank collapse
1850-
1900
Land
Clearance
Extensive
siltation
Navigation
Shoaling
1900-
1950
Dams,
irrigation.
Flood scouring,
reduced flows
Bank collapse.
Flow records.
1950-
1990
Extraction
STW eff.
Bank scouring,
WQ, ecology
Change in Depth
Increased nutrients
1990- Urban Dev
Recreation
Turbidity,
Nutrients.
Aquatic weed
problems

18. Community concerns and
responses.

19. A Chronology of Community Concerns
These include:
River bank clearance 1800s
• Silting and navigation issues 1880s
• Sewage Pollution (Health) 1900s
• Turbidity 1930s
• Noxious weeds 1940s
• Algal Blooms (Blue Green) 1980s
• Weed Blooms 1990s

20. Hawkesbury River First Recorded Management
Response (1803)

21. Recent actions to improve waterway
quality of the Hawkesbury River include:
Policies/Acts/Regulations
Sydney REP No. 20-Hawkesbury-Nepean River
(No. 2-1997)
Hawkesbury-Nepean River Act 2009 No. 14
(repealed 2012)
Hawkesbury-Nepean Catchment Management
Trust Regulation (1999-2003)
Catchment Management Authorities Act 2003

22. Recent actions to improve waterway quality of
the Hawkesbury River include:
Organisations Established
1983 Joint Councils Hawkesbury River Committee
1989 Nepean-Hawkesbury River Catchment
Management Committee
1993 Hawkesbury-Nepean Catchment
Management Trust
2006-2011 Office of Hawkesbury-Nepean
2011-2013 Hawkesbury Nepean CMA now part of
Sydney CMA

23. Recent strategies/programs to improve waterway
quality of the Hawkesbury River include:
1986 Nutrient Removal Program - (MWS&DB)
1996 Phosphorus Action Program HNCMT
1997 Erosion & sediment control program HNCMT
2001 Strategic Management Plan for the H-N Catchment
& River System. (By HNCMT).
2006 River restoration project. HNCMT. (Erosion, bank
restoration)
2007 H/N Catchment Weed Management Strategy OHN
2009 Hawkesbury Nepean River Recovery Program. OHN
2012-2023 Hawkesbury-Nepean Catchment Action Plan.
HNCMA

24. Outcomes

25. Control of Nutrient Pollution
0
0.5
1
1.5
2
2.5
3
3.5
4
1940 1950 1960 1970 1980 1990 2000 2010 2020
Nutrient Data, Wilberforce mg/l (CSIRO, SPCC, SCA)
Nitrogen Total (mg/L) Phosphorus Total (mg/L)

26. Control of Nutrient Pollution
0
5
10
15
20
25
30
35
40
45
50
1940 1950 1960 1970 1980 1990 2000 2010 2020
Suspended Materials, Wilberforce (SPCC, SCA)
Chlorophyll-a (ug/L) Suspended Solids (mg/L)

27. Summary
Time Event Response Status
1793-
50
Bank
Clearance
Collapse Continuing
1850-
1900
Catchment
Clearance
Sedimentation Largely Stable
1900-
1950
Dam
Construction
Bank Erosion
Flow impact
Status quo
1950-
1990-
2030-
Urban Growth Sewage
Pollution
Urban Runoff
Controlled?
Expanding

28. Post-European settlement of Sydney.
Department of Planning and Infrastructure (2006). ‘Draft Sydney Metropolitan Strategy 2006’).
Pre 1917. 1917-1945. 1945-76. 1976-2005. 2005-

29. Conclusions
• Responses in waterway condition can be linked
to catchment activities and actions to improve
river health.
• Many actions or management practices have
not been or are not capable of assessment.
• The development of a framework to assess
future management proposals for protection
and remediation is recommended.
• This should include:
1. capability of benefit cost assessment
2. investigation of legal rights for the river .

30. Thankyou