13th August 2019
NSW MDB Porous and Fractured Rock Groundwater Status Update
MDB Porous and Fractured Rock Groundwater Status Update
• Groundwater Occurrence • MDB SDL Groundwater Resource Units • Number of registered works & bore
distribution • Measured usage against WSP and SDL
extraction limits. • Groundwater trading • Groundwater monitoring • Conclusions
The water cycle
Aquifer Types
Aquifer porosity
Porous rock vs Fractured rock
Conceptual model of groundwater flow
Gunnedah-Oxley Basin Cross Section –
Conceptual Model – Bioregional Assessment, 2018
Cross Section – Coolanbilla Mtn to Spring Ridge
Porous Rock - Number of Water Supply Bores in WRP Area
SDL Resource Unit Basic Rights Production Bores Local Water Utility Total
Gunnedah-Oxley Basin MDB 4100 283 5 4388
Western Porous Rock 759 54 3 816
Sydney Basin MDB 359 41 0 400
Oaklands Basin 0 0 0 0
Total 5218 378 8 5604
Porous Rock - Measured Usage, SDL and WSP LTAAEL extraction limits.
SDL Resource
Unit Groundwater
Source
Current LTAAEL (ML/yr)
New LTAAEL /
SDL volume (ML/yr)
Aquifer Access
licences (unit shares)
Water Utility access
licences (ML/yr)
Salinity and Water Table
Management access
licences (ML/yr)
Average Annual
Extraction (ML/yr)
Mine Shares
Gunnedah-Oxley Basin
MDB
Gunnedah- Oxley Basin
MDB 205,640 127,500 23,109 480 0 5,106 Coal
5,700
Western Porous Rock
Western Murray
Porous Rock 530,486 226,000 21,529 390 13,985 4,988
Yes, mineral sands
Sydney Basin MDB
Sydney Basin MDB 60,443 19,100 5,443 0 0 Not
monitored 0
Oaklands Basin
Oaklands Basin 0 2,500 0 0 0 Not
monitored 0
Information on the controlled allocation process is at:
Current Extraction Limit
Allocated Shares
https://www.industry.nsw.gov.au/water/licensing-trade/licences/controlled
Gunnedah-Oxley Basin Groundwater Source
New Extraction limit / Basin Plan SDL
Northern Fractured Rock - Measured Usage, SDL and WSP LTAAEL extraction limits.
SDL Resource Unit Groundwater Source
Current LTAAEL (ML/yr)
New LTAAEL / SDL volume (ML/yr)
Aquifer Access
licences (unit
shares)
Water Utility access licences
(ML/yr)
Average Annual
Extraction (ML/yr)
Inverell Basalt Inverell Basalt 25,807 4,150 3,382 0 324
Liverpool Ranges Basalt
Liverpool Ranges Basalt
MDB 19,075 2,160 422
0 57
Warrumbungle Basalt
Warrumbungle Basalt 5,710 550 71 0 No data
New England Fold Belt
New England Fold Belt MDB 204,784 39,253
55,100
9057 614 75
Peel Fractured Rock 71,218 15,847 11,008 548 998
Porous Rock - Temporary Trade 71T dealings Since 2012
SDL Resource Unit 2012-2013 2013-2014 2014-2015 2015-2016 2016-2017 2017-2018
Gunnedah-Oxley Basin MDB
1 trade (187.5ML)
4 trades (721ML)
5 trades (1059.5 ML)
3 trades (1062ML)
6 trades (1511.5ML)
6 trades (1196ML)
Western Porous Rock
1 trade (200ML)
2 trades (1160ML)
1 trade (900ML)
2 trades (300ML)
2 trades (2500ML)
2 trades (2500ML)
Sydney Basin MDB 0 0 0 0 0 0
Oaklands Basin 0 0 0 0 0 0
Porous Rock - Permanent Trade dealings since 2012
SDL Resource Unit 2012-2013 2013-2014 2014-2015 2015-2016 2016-2017 2017-2018
Gunnedah-Oxley Basin MDB 0 1 trade
(150ML) 1 trade
(206ML) 1 trade
(300ML) 2 trades (105ML) 0
Western Porous Rock 0 0 0 0 0 0
Sydney Basin MDB 0 0 0 0 0 0
Oaklands Basin 0 0 0 0 0 0
Drawdown and Bore Interference
Example hydrograph
Groundwater Monitoring
Gunnedah-Oxley Basin (Spring Ridge Management Zone): Site GW036333 Located approx. 11 km SSE of Spring Ridge.
Gunnedah-Oxley Basin (Spring Ridge Management Zone): Site GW036315 Located on Wilmots Rd approx. 15 km SSW of Spring Ridge.
Department Groundwater Monitoring
Site GW036972 Gunnedah-Oxley Basin
Gunnedah-Oxley Basin (Other Management Zone): Site GW036315 Located on Share Farms Rd approx. 11 km W of Willow Tree off Merriwa Rd.
Conclusions • The shares allocated in these water sources is generally well below
their extraction limit – this is due to low yields and varying water quality
• There is limited use of groundwater for irrigation, commercial and town water supply purposes
• Groundwater trading is very limited
• There is no concern for water level declines outside natural variations
• Groundwater extractions are significantly below extraction limits for all each of the 4 water sources
Questions?
Chris Rumpf
Groundwater Occurence
• When rain hits the ground it can generally either: • Evaporate • Runoff into a surface water system • Be taken up by plants • Provide moisture to the soil or the free draining system, or • Pass through the free draining system into the water table
• When it reaches the water table, it is now part of the groundwater system.
• This process is described as “recharge” • Groundwater flow is now governed by aquifer properties and
water quality is impacted by the host rock
Groundwater and aquifers
• Groundwater is stored in aquifers (water bearing formations), which are broadly classed as:
• Alluvial • Porous rock • Fractured rock
• The physical characteristics of an aquifer determine how easy and how much water can be extracted from the aquifer
• The chemical characteristics of the aquifer are imparted to the groundwater including salts, which can result in groundwater being too salty for an intended purpose
Aquifer types
Alluvial Unconsolidated material, generally associated with surface water deposits, usually containing fresher water quality due to a shorter water residence time. Typically units are recent to less than 1 million years old Porous Rock Typically associated with sedimentary basins, being made up of consolidated sediments, with primary and secondary porosity. Location of deposition can dictate quality of water, eg marine environment can impart salts. Typically units vary from 50 – 350 million years in age. Fractured Rock Typically any rock that does not contain primary porosity. Includes younger rocks such as basalts through to older metasediments and granites, as such units can be >600 million years old. Water quality and yields can be highly variable.
Department Groundwater Monitoring
Site GW036669 Western Porous Rock
Spring Ridge Geology
Spring Ridge Lots
Additional Fractured Rock Stats
Measured Usage, SDL and WSP LTAAEL extraction limits.
SDL Resource Unit
Groundwater Source
SDL volume (ML/yr)
LTAAEL (ML/yr)
Aquifer Access Share Component (unit shares)
Town Water / Water
Utility Share Component
(ML/yr)
Salinity and Water Table
Management (ML/yr)
Stock and Domestic
Access (ML/yr)
Average Annual
Extraction (ML/yr)
Adelaide Fold Belt (GS10)
Adelaide Fold Belt MDB 6,900 26,018 3,627 0 0 0 No data
Kanmantoo Fold Belt (GS19)
Kanmantoo Fold Belt
MDB 18,700 121,524 750 5 5 5 500
Lachlan Fold Belt (GS20)
Lachlan Fold Belt MDB --- 875,652 66,871 2838 236 0 4,244
Yass Catchment --- 26,163 2941.5 258 0 3 406
TOTAL 259,000 901,815 69812.5 3096 236 3 4650
New England Fold Belt (GS37)
New England Fold Belt
MDB --- 204,784 9057 614 0 0 122
Measured Usage, SDL and WSP LTAAEL extraction limits
SDL Resource Unit
Groundwater Source
SDL volume (ML/yr)
LTAAEL (ML/yr)
Aquifer Access Share
Component (unit
shares)
Town Water / Water Utility Share
Component (ML/yr)
Salinity and Water Table
Management (ML/yr)
Stock and Domestic
Access (ML/yr)
Average Annual
Extraction (ML/yr)
Inverell Basalt (GS18)
Inverell Basalt 4,150 25,807 3,382 0 0 0 324
Liverpool Ranges Basalt
(GS22)
Liverpool Ranges Basalt MDB
2,160 19,075 422
0 0 0 13
Orange Basalt (GS39) Orange Basalt 10,700 16,208
9,561
250 0 0 550
Warrumbungle Basalt (GS49)
Warrumbungle Basalt
550 5,710 71 0 0 0 No data
Young Granite (GS51) Young Granite 7,110 9,529 6,368 0 0 0 1,030