CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES STORMWATER DRAINAGE DESIGN D5 DESIGN GUIDELINES CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5 ISSUE: NO:4 Jan 2017
TABLE OF CONTENTS CLAUSE CONTENTS PAGE GENERAL...4 D5.01 SCOPE... 4 D5.02 OBJECTIVES... 4 D5.03 REFERENCE AND SOURCE DOCUMENTS... 4 HYDROLOGY...5 D5.04 DESIGN RAINFALL DATA... 5 D5.05 CATCHMENT AREA...30 D5.06 RATIONAL METHOD...30 D5.07 OTHER HYDROLOGICAL MODELS...31 HYDRAULICS...31 D5.08 HYDRAULIC GRADE LINE...31 D5.09 CONDUITS (PIPES / BOX CULVERTS)...31 D5.10 PITS...32 D5.11 OVERLAND FLOW...32 D5.12 OPEN CHANNELS...32 D5.13 MAJOR STRUCTURES...33 D5.14 RETARDING BASINS...34 D5.15 RURAL DESIGNS...34 INTER ALLOTMENT DRAINAGE...34 D5.16 INTER ALLOTMENT DRAINAGE...34 DETAILED DESIGN...35 D5.17 STORMWATER DISCHARGE...35 CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-2 ISSUE: NO:4 Jan 2017
D5.18 PIPE MATERIAL...35 D5.19 SUBSOIL DRAINAGE...36 D5.20 EASEMENTS AND AGREEMENTS...36 D5.21 WATER QUALITY ISSUES...36 Keeping the Capricorn Municipal Development Guidelines up-to-date The Capricorn Municipal Development Guidelines are living documents which reflect progress of municipal works in the Capricorn Region. To maintain a high level of currency that reflects the current municipal environment, all guidelines are periodically reviewed with new editions published and the possibility of some editions to be removed. Between the publishing of these editions, amendments may be issued. It is important that readers assure themselves they are using the current guideline, which should include any amendments which may have been published since the guideline was printed. A guideline will be deemed current at the date of development approval for construction works. CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-3 ISSUE: NO:4 Jan 2017
GENERAL D5.01 SCOPE 1. This section sets out the guidelines for the design of stormwater drainage systems for urban and rural areas. D5.02 OBJECTIVES 1. The objectives of stormwater drainage design are as described in QUDM Section 1.03. D5.03 REFERENCE AND SOURCE DOCUMENTS (a) Council Specifications C220 - Stormwater Drainage - General C221 - Pipe Drainage C222 - Precast Box Culverts C223 - Drainage Structures C224 - Open Drains including Kerb & Gutter (b) (c) Australian Standards AS 1254 - Unplasticised PVC (upvc) pipes and fittings for stormwater or surface water applications. AS 2032 - Code of practice for installation of upvc pipe systems. AS 3725 - Loads on buried concrete pipes. AS 4058 - Precast concrete pipes. AS 4139 - Fibre reinforced concrete pipes and fittings. QLD State Authorities Department of Natural Resources & Water (jointly with Brisbane City Council & IPWEAQ). - Queensland Urban Drainage Manual, Volume 1, Second Edition 2007. Department of Main Roads. - Road Drainage Design Manual (2002). (d) Other AUSTROADS - Guide to Bridge Technology Inst. of Eng. - Australian Rainfall and Runoff - A guide to flood estimation. Aug 1987. Institute of Municipal Engineering Australia, QLD Division. - Standard Drawings, 1997 Sangster, WM., Wood, HW., Smerdon, ET., and Bossy, HG. - Pressure Changes at Storm Drain Junction, Engineering Series, Bulletin No. 41, Eng. Experiment Station, Univ. of Missouri 1958. Hare CM. - Magnitude of Hydraulic Losses at Junctions in Piped Drainage Systems. Transactions, Inst. of Eng. Aust., Feb. 1983. Concrete Pipe Association of Australia - Concrete Pipe Guide, charts for the selection of concrete CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-4 ISSUE: NO:4 Jan 2017
pipes to suit varying conditions. Henderson, FM. -Open Channel Flow, 1966. Chow, Ven Te - Open Channel Hydraulics, 1959. John Argue - Australian Road Research Board Special Report 34 - Stormwater drainage design in small urban catchments: a handbook for Australian practice. Australian National Conference On Large Dams, Leederville WA. - ANCOLD 1986, Guidelines on Design Floods for Dams. STORMWATER DRAINAGE DESIGN HYDROLOGY D5.04 DESIGN RAINFALL DATA 1. Design Intensity Frequency Duration (IFD) rainfall data should be developed in accordance with Australian Rainfall and Runoff for the area where the design is to take place. Intensities derived from Figures D5.04.01 to D5.04.23 may be used for applicable locations. I-F-D Data Table D5.04.1 Design Rainfall Intensity Council Location Use Figure Banana Shire Banana D5.04.01 Banana Shire Camboon D5.04.02 Banana Shire Biloela D5.04.03 Banana Shire Barfield D5.04.04 Banana Shire Moura D5.04.05 Central Highlands Regional Former Bauhinia Shire Area D5.04.06 Central Highlands Former Emerald Shire Area Regional and Duaringa Shire Area D5.04.07 Central Highlands Former Peak Downs Shire Regional Area D5.04.08 Gladstone Regional Agnes Water D5.04.09 Gladstone Regional Calliope D5.04.10 Gladstone Regional Gladstone D5.04.11 Gladstone Regional Miriam Vale D5.04.12 Isaac Regional Clermont D5.04.13 Isaac Regional Dysart D5.04.14 Isaac Regional Middlemount D5.04.15 Isaac Regional Moranbah D5.04.16 Isaac Regional Nebo D5.04.17 Isaac Regional St Lawrence D5.04.18 Livingstone Shire Samuels Hill D5.04.19 Livingstone Shire Yeppoon D5.04.20 Maranoa Regional All areas (based on Roma) D5.04.21 Rockhampton Regional West of Bruce Highway and Berserker Ranges D5.04.22 Rockhampton Regional East of Bruce Highway and Berserker Ranges D5.04.23 CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-5 ISSUE: NO:4 Jan 2017
CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-6 ISSUE: NO:4 Jan 2017
Figure D5.04.01 Design Rainfall Intensity Diagram for Banana Shire Council (Township of Banana) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-7 ISSUE: NO:4 Jan 2017
Figure D5.04.02 Design Rainfall Intensity Diagram for Banana Shire Council (Township of Camboon)) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-8 ISSUE: NO:4 Jan 2017
Figure D5.04.03 Design Rainfall Intensity Diagram for Banana Shire Council (Township of Biloela) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-9 ISSUE: NO:4 Jan 2017
Figure D5.04.04 Design Rainfall Intensity Diagram for Banana Shire Council (Township of Barfield) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-10 ISSUE: NO:4 Jan 2017
Figure D5.04.05 Design Rainfall Intensity Chart for Banana Shire Council (Township of Moura) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-11 ISSUE: NO:4 Jan 2017
Figure D5.04.06 Design Rainfall Intensity Diagram for former Bauhinia Shire Council CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-12 ISSUE: NO:4 Jan 2017
Figure D5.04.07 Design Rainfall Intensity Diagram for former Emerald and Duaringa Shire Council areas CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-13 ISSUE: NO:4 Jan 2017
Figure D5.04.08 Design Rainfall Intensity Diagram for former Peak Downs Shire Council area CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-14 ISSUE: NO:4 Jan 2017
Figure D5.04.09 Design Rainfall Intensity Diagram for Gladstone Regional Council (Township of Agnes Water) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-15 ISSUE: NO:4 Jan 2017
Figure D5.04.10 Design Rainfall Intensity Diagram for Gladstone Regional Council (Township of Calliope) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-16 ISSUE: NO:4 Jan 2017
Figure D5.04.11 Design Rainfall Intensity Diagram for Gladstone Regional Council (Township of Gladstone) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-17 ISSUE: NO:4 Jan 2017
Figure D5.04.12 Design Rainfall Intensity Diagram for Gladstone Regional Council (Township of Miriam Vale) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-18 ISSUE: NO:4 Jan 2017
Figure D5.04.13 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of Clermont) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-19 ISSUE: NO:4 Jan 2017
Figure D5.04.14 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of Dysart) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-20 ISSUE: NO:4 Jan 2017
Figure D5.04.15 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of Middlemount) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-21 ISSUE: NO:4 Jan 2017
Figure D5.04.16 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of Moranbah) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-22 ISSUE: NO:4 Jan 2017
Figure D5.04.17 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of Nebo) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-23 ISSUE: NO:4 Jan 2017
Figure D5.04.18 Design Rainfall Intensity Diagram for Isaac Regional Council (Township of St Lawrence) STORMWATER DRAINAGE DESIGN CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-24 ISSUE: NO:4 Jan 2017
Figure D5.04.19 Design Rainfall Intensity Diagram for Livingstone Shire Council (Samuels Hill area) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-25 ISSUE: NO:4 Jan 2017
Figure D5.04.20 Design Rainfall Intensity Diagram for Livingstone Shire Council (Township of Yeppoon) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-26 ISSUE: NO:4 Jan 2017
Figure D5.04.21 Design Rainfall Intensity Diagram for Maranoa Regional Council CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-27 ISSUE: NO:4 Jan 2017
Figure D5.04.22 Design Rainfall Intensity Chart for Rockhampton Regional Council (Applicable for all localities West of Bruce Highway and Berserker Ranges) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-28 ISSUE: NO:4 Jan 2017
Figure D5.04.23 Design Rainfall Intensity Diagram for Rockhampton Regional Council (Applicable for all localities East of Bruce Highway and Berserker Ranges) CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-29 ISSUE: NO:4 Jan 2017
2. Design Average Recurrence Interval (ARI) shall be in accordance with Table D5.04.2. A R I Table D5.04.2 Design Average Recurrence Intervals Design ARI (Years) Major System Minor System Central Business & Commercial 100 10 Industrial 100 5 Urban Residential (High Density greater than 20 dwelling units/ha) 100 5 Urban Residential (Low Density greater than 5 & up to 20 dwelling 100 5 units/ha) Rural Residential -2 to 5 dwelling units/ha 100 2 Open Space Parks, etc 100 1 Notes: 1. The design ARI for the minor drainage system in a major road shall be that indicated for the major road, not that for the Development Category of the adjacent area. 2. Culverts under roads should be designed to accept the full flow for the minor system ARI shown. In addition the designer must ensure that the 100 year ARI backwater does not enter properties upstream. If upstream properties are at a relatively low elevation it may be necessary to install culverts of capacity greater than that for the minor system ARI design storm to ensure flooding of upstream properties does not occur. In addition the downstream face of the causeway embankment may need protection where overtopping is likely to occur. 3. The terms used in this table are described in the QUDM Glossary and/or Table 7.02.2 of QUDM 2007. D5.05 CATCHMENT AREA 1. The catchment area of any point is defined by the limits from where surface runoff will make its way, either by natural or man made paths, to this point. Consideration shall be given to likely changes to individual catchment areas due to the full development of the catchment. Catchment Definition 2. The catchment boundary shall be determined by using the most accurate information available subject to Local Government approval. This shall be presented to Local Government in a contour map along with the source of information. 3. Catchment area land use shall be based on current available zoning information or proposed future zonings, where applicable. D5.06 RATIONAL METHOD 1. Rational Method calculations to determine peak flows shall be carried out in accordance with QUDM Section 4.03 2. All calculations shall be carried out by a qualified person experienced in hydrologic and hydraulic design. Qualified Person 3. Coefficients of discharge shall be calculated in accordance with QUDM Section Runoff CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-30 ISSUE: NO:4 Jan 2017
4.05. Co-efficients 4. Where the flow path is through areas having different flow characteristics or includes property and roadway, then the flow time of each portion of the flow path shall be calculated separately. 5. The maximum time of concentration in an urban area shall be 20 minutes unless sufficient evidence is provided to justify a greater time. Time of Concentration 6. Flow paths to pits shall be representative of the fully developed catchment considering such things as fencing and the likely locations of buildings. Consideration shall be given to likely changes to individual flow paths due to the full development of the catchment. 7. Mannings n surface roughness co-efficients in accordance with QUDM shall generally be derived from information in Chapter 14 of AR&R 1987. Overland Flow Retardance D5.07 OTHER HYDROLOGICAL MODELS 1. Computer analysis programs may be used as long as the requirements of QUDM are met, summaries of calculations are provided and details are given of all program input and output. Alternative Models HYDRAULICS D5.08 HYDRAULIC GRADE LINE 1. Hydraulic calculations shall generally be carried out in accordance with QUDM and shall be undertaken by a qualified person experienced in hydrologic and hydraulic design. The calculations shall substantiate the hydraulic grade line adopted for design of the system and shown on the drawings. Summaries of calculations are to be provided with the design including listings of all program input and output. A sample of a summary sheet for hydraulic calculations is given in QUDM Volume 2. Qualified Person Calculations 2. The "major" system shall provide safe, well-defined overland flow paths for rare and extreme storm runoff events while the "minor" system shall be capable of carrying and controlling flows from frequent runoff events. 3. Downstream water surface level requirements are given below:- (a) Known hydraulic grade line level from downstream calculations including pit losses at the starting pit in the design event. Downstream Control (b) (c) Where the downstream starting point is a pit and the hydraulic grade line is unknown, a level of 0.15m below the invert of the pit inlet in the downstream pit is to be adopted. Where the outlet is an open channel or natural watercourse the tailwater level shall be established by calculation of the coincident rainfall event in the open channel or natural watercourse. 4. The water surface in drainage pits shall be limited to 0.150m, below the gutter invert for inlet pits and 0.150m below the underside of the lid for junction pits. Water Surface Limits D5.09 CONDUITS (PIPES / BOX CULVERTS) 1. Minimum conduit sizes are given below: Conduit Sizes CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-31 ISSUE: NO:4 Jan 2017
The minimum pipe size shall be 375mm diameter. The minimum box culvert size shall be 600mm wide x 300mm high. STORMWATER DRAINAGE DESIGN 2. Minimum cover to conduits shall be in accordance with the manufacturer s specifications, wherever possible a minimum cover of 600mm is preferred. 3. Conduit classes shall be determined in accordance with manufacturer s recommendations. 4. The minimum vertical and horizontal clearance between stormwater conduits and other services shall be 150mm. 5. In areas where any part of the pipe is below AHD RL 3.00 and likely to be exposed to saltwater, conduits shall have saltwater cover to reinforcement. Conduit Classes Clearance Saltwater Cover D5.10 PITS 1. Inlet Pits shall be spaced so that the gutter flow width is limited in accordance with QUDM Section 7.04 and so that the inlet efficiency is not affected by adjacent inlet openings. Preference shall be given to the location of drainage pits at the upstream side of allotments. Spacing 2. Access chambers shall be provided in accordance with QUDM Section 7.06. 3. Gully inlet shall be local authority approved proprietary inlet structures. Current approved products are CM Pits and Drainways. Alternative products are by Local Government approval. Inflow capacities shall be in accordance with the manufacturer s specifications with Blockage Factor applied in accordance with QUDM Section 7.05. Approved Gully Inlets D5.11 OVERLAND FLOW 1. The major system shall be designed generally in accordance with QUDM. Where overland flow is to be transferred from the road network into drainage reserve, open space or parkland, dedicated drainage flow paths must be provided of minimum width of 5m. In urban areas, the transfer of overland flow from road reserve to open space shall not be permitted within private property. Overland Flow 2. Overland flow paths shall be located in accordance with QUDM. 3. Drainage flow paths do not generally count as useful park contribution areas. Refer to Local Governments planning scheme policies for this information. D5.12 OPEN CHANNELS 1. Generally, open channels will only be permitted where they form part of the trunk drainage system and shall be designed to have smooth transitions with adequate access provisions for maintenance and cleaning. Where Local Government permits the use of an open channel to convey flows from a development site to the receiving water body, such a channel shall comply with the requirements of this Guideline. 2. Design of open channels shall be generally in accordance with QUDM Section 9.00. Open channels will be designed to contain the major system flow less any flow that is contained in the minor system, with an appropriate allowance for blockage of the minor system. 3. A minimum longitudinal grade 0.5% applies for open channels. Safety Minimum Grade 4. Friction losses in open channels shall be determined using Mannings "n" values Channel CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-32 ISSUE: NO:4 Jan 2017
given below:- Mannings "n" Roughness Co-efficients for open channels shall generally be derived from information in Chapter 14 of AR&R 1987. Mannings "n" values applicable to specific channel types are given below:- Concrete Pipes or Box Sections 0.013 Concrete (trowel finish) 0.014 Concrete (formed without finishing) 0.016 Sprayed Concrete (gunite) 0.018 Bitumen Seal 0.018 Bricks or pavers 0.015 Pitchers or dressed stone on mortar 0.016 Rubble Masonry or Random stone in mortar 0.028 Rock Lining or Rip-Rap 0.028 Corrugated Metal 0.027 Earth (clear) 0.022 Earth (with weeds and gravel) 0.028 Rock Cut 0.038 Short Grass 0.033 Long Grass 0.043 Roughness Channel Roughness 5. Where the product of average Velocity and average flow Depth for the design flow rate is greater than 0.4m 2 /s, the design will be required to specifically provide for the safety of persons who may enter the channel. 6. Maximum side slopes on grassed lined open channels shall be 1 in 6 side slopes unless otherwise approved by Local Government, channel inverts shall generally have minimum cross slopes of 1 in 20. 7. Low flow provisions in open channels (man-made or altered channels) will require low flows to be contained within a pipe system at the invert of the main channel. A minimum size of 375mm is required. Scouring velocities in the pipe shall be obtained at 2 year ARI. Subsurface drainage shall be provided in grass-lined channels to prevent waterlogging of the channel bed. The width of the invert shall be sufficient to accommodate the full width of a tractor and slasher. Local Government approval is required for situations where low flow pipes are not required and subsoil drainage will suffice. 8. Transition in channel slopes to be designed to avoid or accommodate any hydraulic jumps due to the nature of the transition. 9. Armouring, if required, shall be designed to suit the maximum flow velocity up to an ARI 2 year storm event. Refer Standard Drawing CMDG-D-60. Side Slopes Low Flows Hydraulic Jumps Armouring 10. The preferred solutions for open channel treatments are natural treatments including the use of rock lining, vegetation treatments and soft engineering solutions. D5.13 MAJOR STRUCTURES 1. All Cross Road Drainage structures shall be designed for the ARI storm event appropriate for the class of road in accordance with QUDM Table 7.02.1. Minor Roads shall be defined as Access Place and Access Streets with Major Road defined as Collector Street and greater. 2. For bridges a minimum clearance of 0.5m between the design ARI flood level and the underside of any major structure superstructure is required to allow for passage of debris without blockage. 3. All bridges shall be designed for debris loading for a maximum probability flood event Afflux Freeboard Bridges CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-33 ISSUE: NO:4 Jan 2017
4. Certified structural design shall be required on bridges and other major culvert structures and may be required on some specialised structures. Structural design shall be carried out in accordance with AUSTROADS Bridge Design Code. D5.14 RETARDING BASINS 1. Retarding Basins shall be designed in accordance with QUDM Section 5.00. D5.15 RURAL DESIGNS 1. For developments in rural areas refer Queensland Department of Main Roads Road Drainage Design Manual (2002) or Local Government specific guidelines. INTER ALLOTMENT DRAINAGE D5.16 INTER ALLOTMENT DRAINAGE 1. Inter allotment drainage shall be provided to any lot where it cannot be satisfactorily demonstrated that roofwater drainage associated with building construction on that lot, could be reasonably connected to the frontage kerb and channel. The inter allotment drainage system shall be in accordance with QUDM Design Class 2 or 3 as set out in Table D5.16.1 for the individual Councils. Inter allotment Drainage Requirement (QUDM Design Classes) Table D5.16.1 Inter allotment drainage requirements QUDM Level Special Requirements Banana Shire II (Note 1) Central Highlands Regional II (Note 1) Connection to main is permitted. No grated inlets. Gladstone Regional III (Note 2) Connections must be to pits. Isaac Regional II (Note 1) Livingstone Shire II (Note 1) Maranoa Regional II (Note 1) Rockhampton Regional II (Note 1) Connection to main is permitted. No grated inlets. Note 1: Level III inter allotment drainage may be required by the Local Government in some instances (eg. steep slopes). Note 2: GRC may consider level II inter allotment drainage in low risk circumstances. 2. All inter allotment drainage systems shall be covered by a drainage easement in favour of Local Government of a minimum width in accordance with Table D5.16.2. If the easement is to form part of an overland flowpath for Level 3 interallotment drainage then the width of the easement must be extended to encompass the full flow width. Drainage Easements CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-34 ISSUE: NO:4 Jan 2017
Table D5.16.2 Inter allotment drainage easements Easement Widths (m) min Banana Shire 3 Central Highlands Regional 4 Gladstone Regional 3 Isaac Regional 4 Livingstone Shire 3 Maranoa Regional 4 Rockhampton Regional 3 3. The inter allotment drainage pipe shall be generally on a 0.75m alignment from the rear boundary of the allotment and shall be designed to accept the concentrated drainage from buildings on each allotment for flow rates having a design ARI the same as the minor street drainage system. Alignment 4. In lieu of more detailed analysis, the fraction of impervious surface assumed to be contributing runoff to the inter allotment drain shall be in accordance with QUDM Table 4.05.1. 5. Inter allotment drainage pits shall be located at all changes of direction. Pits and pipes shall be constructed of steel or fibre reinforced concrete. Pits shall be constructed with a concrete lid finished flush with the surface of works. Refer to Standard Drawing CMDG-D-033. 6. Pipes - Minimum Grade - The inter allotment drainage shall have a minimum longitudinal gradient of 0.5%. 7. Inter allotment Drainage Pipe - Relationship to Sewer Mains Where inter allotment drainage and sewer mains are laid adjacent to each other they are to be spaced a minimum 0.75 metres between pipe centrelines. For inter allotment pipes greater than 150 dia the alignment of the sewer shall be increased to maintain the 0.75m spacing. Pits Grade Sewer DETAILED DESIGN D5.17 STORMWATER DISCHARGE 1. Scour protection at culvert or pipe system outlets shall be constructed to minimise erosion. Generally erosion protection shall, as a minimum, be designed in accordance with the Queensland Department of Transport and Main Roads Road Drainage Design Manual (2002), Chapter 5. 2. The discharge protection shall be subject to the performance standard that the requirements of the Environment Protection Act with regard to water quality are fulfilled. Scour EPA D5.18 PIPE MATERIAL 1. The following pipe materials are approved subject to minimum cover and installation requirements stated by the manufacturer: Pipe material CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-35 ISSUE: NO:4 Jan 2017
Steel reinforced concrete pipe and culverts to AS 4058; Fibre Reinforced pipes to AS 4139; and Other pipes will be considered subject to individual Council approval. D5.19 SUBSOIL DRAINAGE 1. Subsoil drainage in Pipe Trenches - Subsoil Drainage shall be provided in pipe trenches as outlined below. 2. In cases where pipe trenches are backfilled with sand or other pervious material, a 3m length of subsoil drain shall be constructed in the bottom of the trench immediately upstream from each pit or headwall. The subsoil drain shall consist of 100mm diameter agricultural pipes, butt jointed, with joints wrapped with hessian or slotted upvc pipe. Subsoil Drain at Pits 3. The upstream end of the subsoil drain shall be sealed with cement mortar, and the downstream end shall discharge through the wall of the pit or headwall. D5.20 EASEMENTS AND AGREEMENTS 1. All drainage infrastructure (including overland flowpaths) within private property shall be encumbered by drainage easements. The easements shall include deed of agreement that outlines each party s rights as the grantor and the grantee. Easements and Agreements 2. Evidence of any Deed of Agreement necessary to be entered into as part of the drainage system will need to be submitted prior to any approval of the engineering plans. Easements will need to be created prior to sealing of survey plans. D5.21 WATER QUALITY ISSUES 1. The developer shall demonstrate how water quality will comply with EPA Qld Water Quality Guidelines Water Quality CAPRICORN MUNICIPAL DEVELOPMENT GUIDELINES D5-36 ISSUE: NO:4 Jan 2017