Question On Notice No. 2170 asked in the Legislative Council on 16 May 2019 by Hon Diane Evers
Question Directed to the: Minister for Regional Development representing the Minister for Water
Parliament: 40 Session: 1
Question
I refer to the proposed Southern Forests Irrigation Scheme (SFIS), and I ask:
(a) is it possible to determine the volume of water run-off from an agricultural property that needs to be reserved for the environment:
(i) if yes to (a), how is this determined; and
(ii) if no to (b), why not;
(b) will the Minister explain why the Department of Water and Environmental Regulation (DWER) revised the amount of unallocated water in the Middle Donnelly catchment down to 351 ML from 1.1 GL (as it was under the 2012 allocation plan) prior to the imposition of the moratorium:
(i) if no to (b), why not;
(c) does DWER factor in land-use changes in their catchment modelling, such as reversion of plantation land to agricultural uses, which is a desirable outcome under the Shire of Manjimup Agricultural Expansion Plan:
(i) if yes to (c), will the Minister please outline how this is integrated into catchment modelling methodologies; and
(ii) if no to (c), why not;
(d) since around 400 ha of plantation is scheduled to be cleared in 2019-2020 in Middle Donnelly, is the runoff coefficient the same value for pastured land, plantation land and native forest when determining the potential of a catchment to yield surface water:
(i) if yes to (d), why; and
(ii) if no to (d), what are the runoff coefficients for:
(A) pastured land;
(B) plantation land; and
(C) native forest; and
(e) in relation to the 'first comes first served' approach to license applications, what is DWER's responsibility to ensure that license applications are intended to be used by landowners on their property, rather than being speculative;
(f) have there been instances where large water licenses have been approved prior to the sale of properties at unusually high prices by district standards; and
(g) does DWER consider the size of applicants' properties in relation to the volume of water requested:
(i) if yes to (g), what criteria are used to assess the relative size of properties and the volume of water requested; and
(ii) if no to (g), why not?
Answered on 6 August 2019
(a) Yes
(i) It is technically possible to determine the volume of water run-off from individual agricultural properties, however the Department of Water and Environmental Regulation does not manage water resources this way. Hydrological modelling to determine water required for the environment and water available for use is decided at a catchment scale rather than a property scale. This is done to ensure the cumulative effect of multiple water users is managed and that adequate water is left in the river to protect the environment.
(ii) Not applicable
(b) The Middle Donnelly catchment is largely State Forest, making up 76 per cent of the catchment. The remaining 24 per cent is classified as freehold land. The Department decided to reserve the water generated from the State Forest area of the catchment for the Southern Forests Irrigation Scheme, with water generated from the freehold land available for use by landholders. Using this approach, the hydrological modelling identified an additional 351 megalitres for licensing. The remaining volume of water available under the Warren-Donnelly surface water allocation plan 2012, 755 megalitres, has been reserved for the Southern Forests Irrigation Scheme. The temporary cap on new water allocations was announced on 20 December 2017 for the Donnelly River catchment to enable a review of water allocation limits by the end of 2018. The decision to revise the allocation limits set under the 2012 Warren Donnelly Surface Water Allocation Plan was made on 12 December 2018.
(i) Not applicable
(c) Yes
(i) The Department uses land use mapping to update the land uses in its catchment modelling. Clearing of plantation, of sufficient scale, will change the hydrology of the catchment. Any change in hydrology will also depend on the crop type or land use the plantation is replaced by. This is why the Department of Water and Environmental Regulation re-assesses land use types periodically as it reviews allocation limits.
(ii) Not applicable
(d) No
(i) Not applicable
(ii) The recent assessment of catchment yields differentiated between forested areas and cleared areas. The runoff coefficients are approximately 10 per cent for forested area and 30 per cent for cleared areas. Mapping of plantation areas showed there is not a significant scale of plantation to affect a change in stream flow should it be cleared.
(A) Generally, 30 per cent. This is subject to change due to rainfall patterns and catchment characteristics such as soil type.
(B) Generally 10 per cent. This is subject to change due to rainfall patterns and catchment characteristics such as soil type.
(C) Generally 10 per cent. This is subject to change due to rainfall patterns and catchment characteristics such as soil type and the composition of the native vegetation.
(e) The Rights in Water and Irrigation Act 1914 Schedule 1 Clause 7(2) sets out the considerations required in assessing an application to capture or take water. Part of these considerations is the use of the water by the applicant. The Department endeavours to ensure the applicant uses the water in a timely and efficient manner on land that they have legal access to.
(f) The Department’s role is limited to the transfer of water entitlements between owners and does not collect information relating to the property sale price.
(g) Considerations are defined in the Rights in Water and Irrigation Act 1914 Schedule 1 Clause 7(2). The size of the property is not one of these considerations, per se. However the assessment process under Clause 7(2) evaluates the efficient use of water applied for in an application and the legal access to land which could be impacted by the property size, soil types and proposed crop types.
(i) Not applicable
(ii) Not applicable