Design Templates Stormwater Calculation Summary

Transcription

1 Infrastructure Technical Specifications Stormwater Calculation Summary F4.1 Site Address: Consent Number: Application by: Total Site Area Prior to Subdivision Lot 1 Area Lot 1 C Design Storm Details ARI Lot 2 Area Lot 2 C Soakage Viable Lot 1 Provide or or Yes/No number 900 mm soakholes metres of 1.0 m*1.5 m*1.5 m rock filled soak trench metres of 1.0 m*1.5 m*1.2 m proprietary trench proprietary units Lot 2 Provide or or number 900 mm soakholes metres of 1.0 m*1.5 m*1.5 m rock filled soak trench metres of 1.0 m*1.5 m*1.2 m proprietary trench proprietary units Detention Allowable runoff flow rate into HCC reticulation litres/second Lot 1 Share % Lot 2 Share % l/s l/s Lot 1 provide Lot 2 provide minimum litres detention minimum litres detention orifice mm diameter orifice mm diameter Version: October 2012 Page 1 of 1

2 Infrastructure Technical Specifications Worksheet 1 Falling Head Percolation Test F4.2 Site Address: Completed by: Date: Qualification: Chartered Engineer Civil Engineer Engineering Technician Engineering Geologist Drain Layer Other Registration number (tick one) Date of test: Season: The following procedure has been carried out Hole kept full for 17 hrs. prior to test Hole kept full for 4 hrs. prior to test Drop in water level recorded at intervals of 30 mins (or less) Test continued for 4 hrs. Test continued until bore empty Test stopped at 0.25 m above base Hole refilled at 0.25 m above base (tick when complete) Signature: Test Details Bore hole reference ref: Diameter of bore D=. mm Depth of bore. mm Time (min) Depth (mm) Time (min) Depth (mm) Calculations Soakage Rate S r = Minimum Gradient * = Y X *a straight line interpolation between last points on graph y/x = Divide by 1000 for m/hr m/hr = mm/hr Version: October 2012 Page 1 of 1

3 Infrastructure Technical Specifications Worksheet 2 Falling Head Percolation Graph F4.3 Site Address: Completed by: Bore ref: Date: Water Depth (mm) Time (hr) Version: October 2012 Page 1 of 1

4 Worksheet 3 Stormwater Runoff Calculation Summary 2 Lot Development F4.4 Site Address: Completed by: Date: Pre-Development Site Runoff Zone Residential Industrial Commercial 5 min storm intensity 2 year 5 year 10 year Pre-climate Change I= mm/hr mm/hr mm/hr Total Site Area A= m 2 Allowable Runoff From Site Q = CIA m3 /s Q allow = X X 3,600,000 = m 3 /s Note: litres/second = [(m 3 /s)*1000] [ l/s] Developed site Lot 1 Zone Residential Industrial Commercial 1 hr storm intensity year year year Post-climate Change I= mm/hr mm/hr mm/hr Lot 1 Area A lot1 = m 2 Equivalent Impervious Area Cover Type Area (m2) Coefficient C Area x C Roof A r = 0.95 Paved A pv = 0.95 Pervious (lawn etc.) A pe = 0.3 A e = (Area x C) Equivalent Runoff Coefficient C eqv = A e = A lot1 Runoff From SiteQ = C eqvia lot m3 /s Q lot1 = X X 3,600,000 = m 3 /s Note: litres/second = [(m 3 /s)*1000] [ l/s] Version: October 2012 Page 1 of 2

5 Worksheet 3 Stormwater Runoff Calculation Summary 2 Lot Development F4.4 Developed site Lot 2 Run-off Zone Residential Industrial Commercial min storm intensity year year year Value from manual I= mm/hr mm/hr mm/hr Lot 2 Area A lot2 = m 2 Equivalent Impervious Area Cover Type Area (m 2 ) Coefficient C Area x C Roof A r = 0.95 Paved A pv = 0.95 Pervious (lawn etc.) A pe = 0.3 A e = (Area x C) Equivalent Runoff Coefficient C eqv = A e A lot2 = Runoff From SiteQ = C eqvia lot m3 /s Q lot2 = X X 3,600,000 = m 3 /s Note: litres/second = [(m 3 /s)*1000] [ l/s] Version: October 2012 Page 2 of 2

6 Worksheet 4 Nominal Soakage Design F4.5 Site Address: Completed by: Date: Area of additional impervious surface m 2 Note this needs to be <= 20 m 2 Describe the general soil type [excavate a 1.0 m square hole, 1.0 m deep in the general area of the proposed soak pit] Fill the hole with water Does the water soak away within 24 hours? Yes Use nominal soak pit as detail available from the City Development Unit No alternative method of disposal possibly required refer to designer. Version: October 2012 Page 1 of 5

7 Worksheet 5 Soakage Design F4.5 Site Address: Completed by: Date: Area for lot number from worksheet 3 A lot m 2 Equivalent Runoff Coefficient from worksheet 3 C eqv Soakage Rate (from worksheet 1) S r m/hr Design storm Duration I mm/hr Depth (d) mm Q=CI equiv A lot_/ m 3 /s Volume in V in =(d/1000) x A m 3 5 min 10 min 20 min 30 min 60 min 1 hr 2 hr 6 hr 12 hr 24 hr 48 hr 72 hr Note for soakage design initially use a one hour storm duration Rainfall Runoff Volume Rc = 10 x Ceqiv x I x Alot = 10 x x x R c = m 3 For a typical soakhole 900 mm diameter Volume of runoff disposed of by V soak = A s x S r x S d Version: October 2012 Page 2 of 5

8 Worksheet 5 Soakage Design F4.5 soakage A s = Soakage Area (for one 900 mm dia soakhole) = m 2 S r = Soakage Rate m/hr S d = Storm Duration 1 hr V soak = x x1 m 3 Volume of runoff held in storage V store = A s x D s x V rf A s = Soakage Area (for on 900 mm dia soakhole) = m 2 D s = Depth of storage (ground water depth 0.5 m or depth of soakhole m) Keep to 2.0 m max depth) V rf = Volume Reduction factor m 0.38 for rock filled hole V store = x x 0.38 m 3 For 1 Soakhole Capacity = V soak + V store m 3 For the site Soakholes required - V soak + V store > R c Therefore R c V soak +V store = Soakholes Version: October 2012 Page 3 of 5

9 Worksheet 5 Soakage Design F4.5 For a typical soak trench (1.0 m wide by 1.5 m long) Volume of runoff disposed of by soakage V soak = A s x S r x S d A s = Soakage Area (1.0 m * 1.5 m) = 1.5 m 2 S r = Soakage Rate m/hr S d = Storm Duration 1 hr V soak = x x1 m 3 Volume of runoff held in storage V store = A s x D s x V rf A s = Soakage Area (1.0 m * 1.5 m) = 1.5 m 2 D s = Depth of storage (ground water depth 0.5 m or depth of trench m) Keep to 2.0 m max depth) V rf = Volume Reduction factor m 0.38 for rock filled hole V store = x x 0.38 m 3 For 1 trench Capacity = V soak + V store m 3 For the site Metre of trench required - V soak + V store > R c Therefore R c V soak +V store = m For proprietary system (dimensions and void figures from manufacturer) (use a 1.0 m length) Volume of runoff disposed of by soakage V soak = A s x S r x S d A s = Soakage Area = m 2 S r = Soakage Rate m/hr S d = Storm Duration 1 hr Version: October 2012 Page 4 of 5

10 Worksheet 5 Soakage Design F4.5 V soak = x x1 m 3 Volume of runoff held in storage V store = A s x D s x V rf A s = Soakage Area m 2 D s = Depth of storage (ground water depth 0.5 m or depth of unit m) Keep to 2.0 m max depth) V rf = Volume Reduction factor m 0. V store = x x m 3 For 1 trench Capacity = V soak + V store m 3 For the site Metre of product required - V soak + V store > R c Therefore R c V soak +V store = m Summary of Calculations Soakhole m deep = Soakholes 1.0 m x 1.5 m Soak trench deep = metres of trench Proprietary system deep = metres of product Version: October 2012 Page 5 of 5

11 Worksheet 6 Detention Tank Design W4.6 Site Address: Completed by: Date: Area for lot number from worksheet 3 A lot m 2 Equivalent Runoff Coefficient from worksheet 3 C eqv Soakage Rate (from worksheet 1) S r m/hr Design storm Duration I mm/hr Depth (d) mm Q=CI equiva l ot_/ m 3 /s Volume in V in=(d/ 1000) x A m 3 Volume Out V out = Q allow x duration in secs m 3 Volume store V in V out m 3 5min 10min 20min 30min 60min 2hr 6hr 12hr 24hr 48hr 72hr Select the largest volume store value and provide at least this sized detention tank. Orifice Plate Design 1. Determine the size and dimensions of the proposed detention tank. 2. Based on the tank dimensions, calculate the height (h) of detained stormwater above the location of the orifice outlet. 3. Calculate the size of the orifice required for the detention tank from the following formula: Version: October 2012 Page 1 of 2

12 Worksheet 6 Detention Tank Design W4.6 Q = CA 2gh Where Q= allowable flow into HCC reticulation C= 0.98 [orifice coefficient] A=area of orifice g=acceleration due to gravity h=height of water above orifice opening Therefore area of orifice required A = Q C 2gh And for a round drilled hole the diameter (D) of orifice required is calculated by A = πr 2 thus r = A and D = 2r π Where D= diameter of circle r = radius of circle π = PI A = area of orifice Version: October 2012 Page 2 of 2

13 Worksheet 7 Combined Detention / Retention Tank Design W4.7 Site Address: Completed by: For single dwellings detention tanks shall provide a minimum of storage for re-use and the volume determined above for detention. For multi-unit development detention tanks shall provide a minimum of storage for re-use and the volume determined above for detention. Version: October 2012 Page 1 of 1

14 Inspection Templates Wetlands and Ponds Checklist F4.8 Location: Administration Details Developer Council Comments Tick if correct Tick if correct Developer name and contact details Detention facility location street address Detention facility type (wetland, dry detention basin) NZ map reference Site plan No Resource consent number (HCC and WRC) Catchment name Contributing catchment area Coordinates for detention facility centre Levels Levels to LINZ datum Top of dam (RL) Top of spillway (RL) Toe of dam (RL) 2 yr ARI water level 10 yr ARI water level 100 yr ARI water level Dimensions Max pond length Max pond width Height of dam in metres to 0.1 m Approx. max water depth to 0.1 m Normal water depth to 0.1 m Operating surface area (m 2 ) Normal storage volume (m 3 ) Spillway details Type Width or diameter Inlet details Type Width or diameter Outlet details Type Width or diameter Flow Design 2 yr return period design m 3 /s 10 yr storm controlled at high level weir (m 3 /s) 100 yr storm at spillway (m 3 /s) Sediment Treatment Estimated suspended solids removal % Estimated sediment accumulation rate in tonnes/year Version: October 2012 Page 1 of 2

15 Inspection Templates Wetlands and Ponds Checklist F4.8 Safety Features Developer Council Comments Tick if correct Tick if correct Planting details Date of planting Plants source Maintenance Requirements Methodology for the on-going and long-term maintenance Estimated cleaning frequency in years Forebay Main pond Details for permanently wet areas Details for surrounding areas How facility should be dewatered and desilted Attachments Location map Legal description of site Detailed scale plan of total contributing catchment Construction detail plans of the pond including all structures Approved As-built plan showing truck maintenance access, working and storage areas WRC resource consent Geotechnical report if applicable Design calculations As-built planting plan Consent compliance reports from WRC All information included in required format Further information required.. Developer.. Date.. Council.. Date Version: October 2012 Page 2 of 2

16 Inspection Templates Wetland and Ponds Inspection/Signoff Checklist F4.9 For completion by Developer prior to requesting: c approval 2. First defects liability inspection 3. Final defects liability inspection 4. Remedial works completion inspection Location: Plan No. : Date Date Date Date Type of Inspection (record 1,2,3 or 4) Tick if satisfactory Tick if satisfactory Tick if satisfactory Tick if satisfactory Pre-inspection 1) Final as-built plans sent to Council 2) Checklists completed for all pipelines and manholes 3) Planting Plan approved by Council Site Meeting 1) Forebay accessible and has all weather access 2) Forebay clear of sludge 3) Boundary pegs sighted 4) Works align with as built plans 5) Spillway/s clear of obstruction 6) Erosion and soil stability 7) Inlet and outlet has structural integrity 8) Plants at least 2.0 m clear of inlet and outlet 9) Planting done to approved planting plan 10) Plant density (approx. 1 per m 2 ) 11) Plants in good condition 12) No plant pests 13) Weed (%) compliant with ITS 14) No notifiable weeds 15) Plants sourced from Waikato Ecological District 16) Safety Features All works satisfactory Remedial work required.. Developer Date. Council Date. Version: October 2012 Page 1 of 1

17 Infrastructure Technical Specifications Quality Assurance Design Certificate F4.10 WATER/WASTEWATER/STORMWATER QUALITY ASSURANCE DESIGN CERTIFICATE Site Address/Project Name Consent Number if known Name of Designer Designers relevant qualifications I hereby confirm that the design of the water reticulation / wastewater provision / Stormwater provision for the above site has been designed in accordance with the following standard Engineering Exception Decisions The following aspects of the design do not meet the requirements of the above standard. (Where standards are not met, please detail the alternative standard achieved). Accepted Y N Signed: Date: Version : October 2012 Page 1 of 1

18 Infrastructure Technical Specifications Pipe Laying Checklist F4.11 WASTEWATER PIPE LAYING CHECKLIST Location: Pipe Laying Checks to to Pipe length (MH To MH) to to to Trench Safety (a) Shield (b) Batter (c) Other Pipe size, quality, approved materials confirmed Set out checked Surveyors name Control points identified Foundation support penetrometer results available if under cutting required, note chainage and CBR results. Record daily level check and confirm on grade Bedding type and surround material Bulk Backfill material Bulk backfill compaction (CBR results from pipe to ground level attached) Alignment control points identified Service connections All service connections in place, taped and staked Connections correctly located horizontally and vertically Connections to main correctly formed As-built measurements taken CCTV pipe inspection Developer Date Version : October 2012 Page 1 of 1 For further information about this form, city.development@hcc.govt.nz

19 Infrastructure Technical Specifications MANHOLE CHECKLIST Location: Manhole Checklist F4.12 to to to to to MH number Manhole Construction Checklist Manhole size, quality, approved materials checked Set out /orientation Sealing strip between risers Benching Height alignment and cross section half pipe lining (wastewater only) Step recesses (if applicable) Flexible joints Cutting and plastering of connections Access details per drawings Step irons including epoxy to outside recesses Bedding type and surround Bulk backfill compaction (CBR results attached) No debris in pipelines Invert of pipes in and out Developer Date Version : October 2012 Page 1 of 1 For further information about this form, city.development@hcc.govt.nz

20 Infrastructure Technical Specifications Trench Backfill Compaction Test Summary Checklist F4.13 TRENCH BACKFILL COMPACTION TEST SUMMARY (attach individual test reports) Location: Plan No: From MH to MH Acceptance Criteria: Tests by: (attached) Analysis of Results Trench backfill completed satisfactorily Trench backfill requires remedial work Developer Date Version: October 2012 Page 1 of 1 For further information about this form, city.development@hcc.govt.nz

21 Infrastructure Technical Specifications CATCHPIT CHECKLIST Location: Stormwater and Wastewater Catchpit Checklist Checklist F4.14 Catchpit Number Catchpit Construction Checklist Catchpit, type, size, quality, approved material checked Set out /orientation Location checked Depth of sump below outlet correct Cutting and plastering of outlet connection Floating debris baffle installed correctly Backfill compaction around pit checked Seating and plastering of surround and grate to sump barrel All silt and debris removed from sump Developer Date Version : October 2010 Page 1 of 1 For further information about this form, city.development@hcc.govt.nz

22 Infrastructure Technical Specifications Final Inspection Pipe Network Checklist F4.15 FINAL INSPECTION FOR STORMWATER AND WASTEWATER NETWORKS Location: _ Plan No: Pre-Meeting Tasks Developer Checklist Council Developer to verify prior to meeting: SW WW Pass 1. All checklists completed 2. All lines flushed out 3. All required CCTV inspections carried out, reviewed and any re-work completed. 4. All manholes checked (eg.infiltration, plastering) 5. Catchpits checked 6. All backfilling complete and tidied up 7. Pressure test completed and witnessed 8. Final as-built plans attached for approval 9. Inspection arranged with Council Site Meeting 1. Inspect all lines 2. Inspect all manholes and catchpits 3. All manholes and catchpits set to level 4. Inspect SW inlet and outlet structures 5. Secondary flowpaths and detention ponds 6. Works on third party land completed to satisfaction of owner 7. Wastewater pumping station 8. Overland flow from adjoining properties not effected 9. All works satisfactorily 10. Remedial work required Developer Council Date Date Version : October 2012 Page 1 of 1 For further information about this form, city.development@hcc.govt.nz