Transport Services Division
STORMWATER
Standards & Guidelines
Instruction to Engineers SAI 24 - DD 302
Department of Planning Transport & Infrastructure (DPTI)
Policies On Assistance To Councils For Stormwater Drainage
Although the drainage of stormwater in South Australia is primarily the
responsibility of Local Government, the State Government or the Department
of Road Transport may provide financial assistance in certain instances. The
Department acts either as the Government’s agent or as the principal in
providing this assistance, depending on the circumstances.
1.
State Government Policy
It is State Government policy to assist Local Government to the extent
of 50% of the estimated or actual cost to Councils of approved
drainage works, whichever is the lesser. This assistance, or subsidy, is
provided from Loan Funds through the Government Stormwater
Drainage Subsidy Scheme. The administration of which has been
delegated by the Government to the Commissioner of Highways as its
agent.
The conditions, procedures, etc., governing this assistance are
explained in full in (Local Government Circular No. 21) but some details
are supplied hereunder for information.
Councils are advised to consult with the Department’s Principal
Drainage Engineer, at the preliminary stage. This is to ensure that
councils avoid unnecessary expenditure in preparing submissions for
works which may be ineligible for subsidy, or which may be
inappropriate in the overall drainage of the catchment area. To qualify
for a subsidy, the drainage works being considered must have an
upstream catchment area in excess of 40 hectares and they must
satisfy accepted engineering principles and standards.
Subsidy works are now subject to a priority setting mechanism.
Councils will be circularised annually for works proposed in the
following financial year. The Principal Drainage Engineer will ensure
the application is technically correct, once the works for the following
financial year have been given a high priority.
The Commissioner will seek Government approval for payment of the
subsidy and advise Councils of the approval and of the Departmental
debit order allocated to the project. Work must not commence prior to
approval.
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Instructions to Engineers SAI 24 - DD302
Departmental supervision of construction of the drainage works will be
undertaken only to preserve the Government’s interest and to ensure
that the work is carried out in accordance with the approved proposal.
Councils are to provide full engineering supervision.
Councils are reimbursed up to the approved subsidy amount upon
receipt and certification of their claims.
2.
Department of Road Transport
It is Departmental policy to assist Councils (subject to certain
conditions), where it can be shown that carriageways under the care,
control and management of the Department will benefit from proposed
stormwater drainage works. For the purpose of this Instruction, a
carriageway under the care, control and management of the
Department shall be read to include any carriageway which is to be
constructed with Departmental funds, and which will be taken over for
maintenance by the Department on completion of the work.
Conditions governing this assistance are as follows:2.1
Departmental assistance will not be given towards drainage
works which attract a subsidy under the Government Stormwater
Drainage Subsidy Scheme, with the possible exception of
bridges and culverts (vide Clause 2.12).
2.2
Departmental assistance should be limited to drainage works
serving a carriageway under the care, control and management
of the Department which are within the road reserve containing
that carriageway. The disposal of water beyond the road
reserve can generally be considered a Council responsibility.
2.3
Where more than one Council is involved in drainage works,
agreement should be reached between the Councils and the
Department on the matter of cost-sharing prior to
commencement of construction.
2.4
All new gullies and their connections which are to serve wholly
or in part carriageways under the care, control and management
of the Department are to be constructed at Departmental
expense. This does not include the main drains.
2.5
All new drains and gullies which will carry no runoff from a
carriageway under the care, control and management of the
Department are to be constructed at Council expense.
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Instructions to Engineers SAI 24 - DD302
2.6
New main drains and junction boxes within the road reserve
which will carry run-off from a carriageway under the care,
control and management of the Department, as well as external
catchment, are to be cost-shared according to the proportions of
the design flow originating from that carriageway and each of the
Council’s areas of responsibility.
2.7
If existing drainage works, which are hydraulically and
structurally adequate, need alteration or relocation because of
Departmental roadworks, the cost of this alteration or relocation
is to be treated in the same way as any other service alteration,
ie. it is to be borne by the Department of Road Transport.
2.8
If existing drainage works are deemed to be hydraulically
adequate but structurally deficient at the time or road
construction, the cost of replacement generally will be borne by
the Department. Councils are to bear the cost of replacement of
any drains which Councils maintain at other times when
structural deficiencies are noted.
2.9
If existing drainage works require upgrading for hydraulic
reasons (whether structurally adequate or not), Departmental
assistance is to be considered subject to conditions (2.1 to 2.6)
above, ie costs may be shared where applicable. The upgrading
may include an addition to or replacement of the existing drain.
2.10 If existing drainage works are both hydraulically and structurally
deficient, but cannot be upgraded in accordance with (2.9) due
to constraints of the remainder of the drainage system, and there
is no likelihood of the system being upgraded by Council.
Replacement with a structurally adequate conduit to the existing
hydraulic standard is to be treated as a “service alteration”, ie at
Departmental expense.
2.11 Where a proposed bridge or culvert crosses a carriageway
under the care, control and management of the Department and
forms part of a future overall Council watercourse improvement
scheme, (as is common in developing urban areas) Council
should be requested to provide details of the required waterway
opening, so the new structure will be compatible with future
channel works.
2.12 In general, all new and replacement bridges and culverts
crossing carriageways under the care, control and management
of the Department will be constructed at Department expense.
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Instructions to Engineers SAI 24 - DD302
Exceptions are as follows:2.12.1
A structure carrying a new artificial drainage line
beneath an existing or proposed roadway will be
constructed at no cost to this Department.
2.12.2
The replacement of a hydraulically deficient, but
structurally adequate structure where a Council is
conducting watercourse improvement works may
be cost-shared.
2.12.3
Simultaneous road widening together with the
conditions described in (2.12.2) may be costshared.
The Extent of Departmental assistance under
(2.12.2) and (2.12.3) should be determined by the
appropriate Regional Engineer in consultation with
the Principal Drainage Engineer if required. Each
such installation is to be considered as a special
case.
Any Government subsidy is based on the nett cost
to Council after Departmental assistance.
3.
Department of Road Transport Procedures
3.1
A plan showing drainage works which will involve
Departmental cost-sharing with Council should be prepared
which clearly shows:




Drains subject to a State Government Subsidy (not
coloured but labelled as not subject to cost-sharing)
Drains which are a Council-only responsibility (blue)
Drains which are a Departmental-only responsibility (red)
Drains subject to cost-sharing (green)
The above plan shall form the basis for all cost-sharing
negotiations with Council. The specified colours shall be used
to present cost-sharing proposals to Council’s in a uniform
manner and in accordance with established convention.
3.2
If a Departmental Design
The Regional Engineer, in conjunction with Design staff as
required, shall seek Council’s agreement in writing to the
drainage design and the proposed allocation of financial
responsibility as shown on the plan. For drains subject to
cost-sharing, the percentages of shared responsibility based
on design flows will be known at this stage.
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Instructions to Engineers SAI 24 - DD302
3.3
If a Council/Consultant’s Design
The Regional Engineer shall seek advice from the Principal
Drainage Engineer as to the acceptability of the design. If the
design is accepted, the plan (in 3.1) shall be prepared and the
Regional Engineer shall write to Council accepting the design
and seeking agreement to the allocation of financial
responsibility shown on the plan. For drains subject to costsharing the percentages of share responsibility based on
design flows will be known at this stage.
3.4
The Regional Engineer shall negotiate with Council to
determine which authority shall manage the drainage
construction. This Department generally shall not manage
large schemes or schemes which are subject to a State
Government subsidy. The managing authority may elect to
construct with day labour forces or to let to contract, but in
either case, this decision shall be subject to the written
acceptance by all parties, of a specification for the work and
subsequently, in the case of a contract, of the recommended
tender.
3.5
The Supervising Engineer, Estimating and Specifications,
shall prepare an estimate or check a Council estimate for the
drainage work.
The estimate shall be prepared for a
particular construction date as advised by the Regional
Engineer and with due consideration of the labour force to be
used for the project. An allowance of 10% for contingencies
and an appropriate allowance for inflation over the
construction period shall be included.
All necessary service alterations shall be included in the
estimate, but the sum total of service alterations shall be
recorded separately.
The estimate shall be prepared in item costs allowing the
determination of cost-sharing in accordance with the plan
(3.1).
The Regional Engineer is required to approve the estimate.
3.6
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Using the estimate for the complete drainage works, but
excluding works eligible for a State Government Subsidy, an
overall percentage share of the remaining works for Council
and this Department can readily be determined with reference
to the plan (3.1).
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Instructions to Engineers SAI 24 - DD302
3.7
The Regional Engineer shall use these percentages and the
corresponding estimated costs as a basis for negotiation with
Council. Should agreement not be reached on this basis, the
Director, Central Operations or Director, Regional Operations
shall be required to ratify the basis on which agreement can
be reached. Agreement in writing, shall be valid only up to
the date for which the estimate was specifically prepared.
Actual costs of service alterations, which are beyond the
control of Council or this Department, are to be included for
sharing at the agreed percentages, even if the actual cost of
the project exceeds the estimated cost.
The agreement, provided all parties concur may be varied at
any time during the construction.
3.8
If the project is completed for less than the estimated amount,
all parties shall pay only their agreed percentage of the actual
cost.
Any overrun on the agreed estimate shall be borne entirely by
the managing authority. However, if the actual cost of the
project exceeds the estimated cost due to service alterations
exceeding their estimates, then this excess expenditure shall
be shared as in (3.7).
3.9
The Regional Engineer shall advise the Senior Accounting
Officer, Financial Reporting, in accordance with Amendment
20 “Sundry Debtor Contributions Payable by Outside
Authorities to enable a contribution debit order to be raised.
If this Department is carrying out the work, the Sundry
Debtors procedure will be in accordance with Amendment 20.
If Council is carrying out the work, the Regional Engineer shall
allocate
the
Departmental
contribution
prior
to
commencement of the work.
The Regional Engineer shall inform the Senior Accounting
Officer, Financial Reporting, immediately following any
variations made to this agreement with Council.
3.10
The managing authority shall be responsible for ordering and
paying for all service alterations required by the drainage
work.
If this Department (as the managing authority) issues an
Order on the E & W S Department, it mush show “Half cost to
the Department” or “Full cost to the Department” depending
on whether the Council contributes to the cost of work
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Instructions to Engineers SAI 24 - DD302
requiring the alteration as shown on the plan (3.1). Refer to
Instructions to Engineers, Section 05.32.
3.11
If Council is carrying out the work, the reinstatement of
trenches on roads under the care, control and management of
the Department should be specified in writing by the
Department. The reinstatement of the surface of the trench
should be carried out by the Department.
In accordance with Section 339 of the Local Government Act,
Council should be advised, that the cost of maintaining the
surface of the trench, due to settlement, may be charged to
Council for a period of twelve months following completion of
the works. Notice of Final Reinstatement is required if this
Section of the Act is enforced.
If a road is to be reconstructed soon after completion of the
drainage works, consideration should be given to including
the reinstatement of the surface in a contract specification
with a suitable maintenance period.
Related matters are contained in Local Government Circulars
No. 20 and 21 respectively.
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Instructions to Engineers SAI 24 - DD302
PORT ROAD
PHILLIPS STREET – EAST TERRACE
DRAINAGE COST SHARING
WESTERN CATCHMENT – THEBARTON COUNCIL
DRAIN
SECTION
27-28
28
28-29
29
29-30
ITEM
375mm
DOUBLE GULLY/JB
375mm
DOUBLE GULLY/JB
375mm
AMOUNT
21.3
1
13.8
1
9.9
RATE
COST
EIA DoT
$109.37
$2,329.58
0.203
EIA
COUNCIL
0.387
%DOT
%COUNCIL
$DoT
$COUNCIL
34
66
$801.53
$1,528.05
$1,951.54
$1,951.54
0
0
100
0
$1,951.54
$0.00
$109.37
$1,509.31
0.122
0.325
27
73
$411.94
$1,097.37
$1,951.54
$1,951.54
0
0
100
0
$1,951.54
$0.00
$109.37
$1,082.76
0.081
0.184
31
69
$330.96
$751.81
30
DOUBLE GULLY/JB
1
$1,951.54
$1,951.54
0
0
100
0
$1,951.54
$0.00
26
DOUBLE GULLY
1
$1,547.93
$1,547.93
0
0
100
0
$1,547.93
$0.00
26-25
375mm x 225mm
57.5
$204.53
$11,760.48
0.166
0.144
54
46
$6,297.54
$5,462.93
DOUBLE GULLY/JB
1
$1,951.54
$1,951.54
0
0
100
0
$1,951.54
$0.00
25-24
25
600mm x 300mm
51
$314.25
$16,026.75
0.344
0.483
42
58
$6,666.51
$9,360.24
24
JUNCTION BOX
1
$1,114.27
$1,114.27
0.344
0.483
42
58
$463.49
$650.78
24-23
600mm x 300mm
50.7
$314.25
$15,932.48
0.344
0.483
42
58
$6,627.29
$9,305.18
23
JUNCTION BOX
1
$1,114.27
$1,114.27
0.344
0.483
42
58
$463.49
$650.78
$100,846.73
$51,210.70
Thebarton Council cost is composed of cost sharing with DoT
DoT cost is composed of cost sharing with Thebarton Council
TOTAL
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$51,210.70
$100,846.73
$152,057.43
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