Probable decreases in future flows

Catchments with large areas in State Forests could have reduced flows in the years ahead. Forestry practices have changed in the Eurobodalla with more trees being taken from coupes, mostly older trees (mainly for woodchips), leaving younger more even aged stands. This will facilitate mechanical harvesting in future probably using the group selection method (virtually clearing each coupe)

We have heard that freehold land in the Upper Tuross catchment could be converted to pine plantations. This would also drastically reduce river flows.

Climate change predictions all seem to point to lower rainfall in SE NSW.

Forestry practices and climate change makes percentile figures unreliable for future flows. Access and trading rules should make allowance for this. For example CTP and Commence TP volumes should be lower than those based on past long term averages. For example, where the 95th percentile is 10ML/day in the Tuross (218008 gauge) it could well be a much lower volume in future.

Increased demand

Population growth will increase demand for town water supplies. The plan should support rules that make Council implement water conservation and the early introduction of restrictions. Eurobodalla Shire Council seems to be heading the right way but extraction from Porters Ck can double in any one year and this is likely to be a time when the river most needs the flow. The connection between groundwater and surface flows needs to be determined, eg for Tuross - town water bores.

Need to limit basic rights and stock and domestic extraction

Subdivision of rural residential land will also put more stress on streams. Dams on drainage lines reduce inflows and properties adjoining rivers and creeks will be able to extract a greater cumulative volume under Basic Rights and Stock and Domestic licences.

There should be volumes attached to these licences with restrictions coming into force in line with those on town water. At the moment people can use large volumes of water for non-commercial purposes eg show gardens. It is also not clear when Stock and Domestic should be classed as commercial - how many animals are allowed before it requires a commercial licence.

Environmental values

Despite "environment" supposed to be at the top of the hierarchy the plans do not seem to reflect this. Proposed CTPs are often not until the 95th percentile flow and in some cases not until the 98th.

The environmental rating appears wrong for some water sources - eg Cockwhy and Boyne are rated medium but have more threatened species and more of their catchments in National Park or State Forest than Clyde (216_15) which has a high environmental rating. Similar inconsistencies occur in other river basins. These lower ratings are then used to justify extraction and trading rules.

Other examples of questionable environmental ratings include the Deua (217_1), Wamban and Burra in the Deua system, and Swamp Ck and Yowrie in the Tuross system.

Wamban, Burra and Mogendoura all have high numbers of threatened species (although Mogendoura's catchment is mainly freehold). Their medium environmental rating influences the proposal to allow trading into the water sources up to 20% of flow stress which will put more pressure on the threatened species.
This also applies to Yowrie which already has licensed extraction of 165ML/year..

It is also proposed to allow trading into water sources that have high environmental ratings eg Reedy Ck, Upper Tuross, Wagonga and Lake Mummuga.

The report for Araluen say that trades should be encouraged out of Araluen into Betowynd and Moodong but the proposed trading rules into these streams say -
Not permitted. Trades are not allowed into or upstream of. No new entitlement
The report for the Upper Deua also says "Should omit upstream from rule as trading is allowed upstream of this subcatchment (consistent with rules for subcatchment 217001)".

Bettowynd and Moodong are the only water sources listed as upstream of the Upper Deua, they have high environmental values and low flows (1ML/day = 70th percentile). Extraction from them should not be increased.

Allowing trades into water sources feeding Wagonga Inlet and Mummuga Lake (up to 20% of flow stress) does not seem sensible. Estuaries are under increasing pressure from surrounding development and need all the flushing they can get. This is particularly so for Mummuga which is closed part of the time.

New rules should not allow more extraction from low flows than current agreements

New rules should not allocate more water from low flows than older water sharing agreements. For example the water sharing agreement for Cockwhy Ck, Mid Clyde and Boyne has a CTP of 26 ML/day (90th percentile) whereas the proposed plan starts with a CTP of 6ML/day (96th percentile) and even at year 10 still has the CTP at only 12ML/day (93rd percentile).
(There is a typing error - CmTP for years 1-5 should be 94th not 64th percentile.)

It is very worrying that a socio-economic study could make these slack rules even slacker. It would be preferable to assist the licence holders to store water than to put the environment of the water sources at risk.

In many Tuross water sources there is a water sharing agreement that introduces full restrictions at 10 ML/day (95th percentile at 218008 gauge). New rules for the first 5 years do not introduce a CTP until flows drop to 3 ML/day (98th percentile) and licencees can commence to pump at 10 ML/day. These rules apply even when the economic risk is low but the environmental risk and hydrological stress are high - Bumbo and Swamp Ck.

The current Water Sharing Agreement for Lower Tuross appears to be much more suited to the needs of both the irrigators and the environment. Where such agreements are in place they should be ratified instead of introducing new rules.

The current CTP in Wadbilliga is 10 ML/day but the proposed CTP is not until the river had dropped to 2 ML/day. (I am assuming that 0.92 correlation between the old gauge at Yowrie and the current one at Wadbilliga means they registered almost the same flow).

Questions

Will the the Independent Pricing and Regulatory Tribunal allow restriction on trading?

What is flow stress? Trading rules allow trading into some water sources up to 10-20% of flow stress.

What is a visible flow? How deep do the flows have to be?
Some pump sites are dug out as stream flows drop - do visible seepages into the holes count as "visible flows".

For the Mid Clyde the current arrangements are confusingly described as --
"Works are not to be used for irrigation unless there is a flow of greater than 29 ML/day at gauge 216002 Clyde River and Brooman which corresponds to a reading on the gauge board of 5.04 m
Works are not to be used for irrigation unless there is a flow of greater than 12 ML/day at gauge 216002 Clyde River and Brooman "
What are "works" and why the two widely different figures for the same thing?

Candlagan, Tomaga and Buckenbowra have a water sharing recommendation CTP of 10ML/day This is supposed to be equivalent to 6ML/day long term average at Buckenbowra. The tables and Key Factors comments for the 3 water sources confusingly say these volumes represent the 90th as well as the 95th percentile flows - what is correct?

What is the current licensed extraction for Mogendoura - 4810ML/yr or 11ML/yr?

Some water sources allow trades within but no new entitlements or trading into the water source. How does this work when there are no licences in the water source? Examples include Gulph , Little & Big Belimbla, Belimbla, Mellion, Mid-Tuross, Woila and Bumberry Creek in the Tuross system. Nelligen, Cyne Mallows, Currowan, Bimbermala, Yadboro, Pigeon House and Holland Creeks are some in the Clyde system.