Flood Damage Report. Central Desert Regional Council Controlled Roads. Yuendumu to Mt Wedge road 57 Kilometre. Yuendumu to Nyirripi road 6 Kilometre

Transcription

1 Flood Damage Report Central Desert Regional Council Controlled Roads Yuendumu to Mt Wedge road 57 Kilometre Yuendumu to Nyirripi road 6 Kilometre Inspected on 29 th,30 th January and 02 nd,03 rd and 04 th February 2015

2 Content Description Page 1. Executive Summary 3 2. Summary of Flood Damage & Costs 4 3. Flood Damage per Road Repair Strategies Appendix A - Rainfall Across Central Desert Regional Council Area Appendix B Council Road Map Appendix C- Photographs Appendix D- CLC Gravel Extraction Royalties 29 Page 2 of 29

3 1. Executive Summary Extent of Damage Heavy rain in mid January 2015 caused major damage to Council s unsealed road network. A year s worth of rain fell in 3 days. See rainfall table Appendix A Only 90km of Council s 500km primary or secondary access roads have proper formation and drainage. All others are flat-bladed tracks, inherited from 1 July These suffered most damage. Sealed roads inside communities suffered only minor damage. Repair cost Total repair cost to Council is $4.98M ex gst to return roads to pre-rain condition. See Summary Table. Council does not have these funds. Council s road budget in 2014/15 is: $449,165 (after admin fees) FAA Roads grant Road maintenance (grading crew) $352,000 Roads to Recovery ($1.76M over 5 yrs) Capital upgrades Council requires NTG Natural Disaster Relief and Recovery Arrangements (NDRRA) funding or similar to achieve road repairs. Council s Road Network Council controls 1,775 km of road network. 1,600 km are access roads between communities. Of these, 220 km are primary access roads the main routes in/out of gazetted communities. 280 km are secondary access roads major routes used by local traffic between communities. Only primary and secondary roads have been audited and costed in this report. Cost calculations Repair costs have been calculated on two rates road contractor rates $12/$8/$4 per m2 for major/moderate/minor and internal Council road crew rates $6.31/$4.05/$1.74 per m2 for same. Council is able to repair the majority of damage using its own local teams and plant, at significantly lower cost than Contractor rates. Only the first 15km of the Yuendumu-Nyirripi Road (borefield access) requires an external contractor due to major gravel and water haulage. If contractors were to undertake all works, the cost would be around $8M. Note the above costs are simply to return roads to their pre-damage condition, i.e. flat blade tracks, not to upgrade to formed, drained roads. Page 3 of 29

4 2. Summary of Flood Damage & Costs Flood Damage Summary Item No Road section Flood damage Estimated cost($) 1 Yuendumu - Nyirripi road (148km) Major scouring and damage at 1.3k to 10.9k,13.2k to 18.2k,56k to 65k and 84k to 87k 2,321, Yuendumu - Yuelumu road (42Km) 3 Yuelumu Access Rd (28Km) Yuelumu - Ten Mile Rd (31Km) Ten Mile - Pulardi- Tanami Rd (18km) Mt Dennison - Willowra backroad (117km) Yuen/Nyir Rd - Mt Wedge - Papunya Rd (65km) Yuendumu sealed section shoulder damage (1.5km) Willowra Primary access(last 20K) Total excluding GST Ti Tree Station (Nturiya) Access Rd (16km) Engawala access creek crossing (1km) Major silting, washouts and floodway damage at 5k to 9k,25k to 28k Minor damages, can be covered from maintenance Major Scouring and floodway damage at 20k to 27k and 28k to 31k Major scouring at 1k to 2k, 6k to 7k and 9k to 10k Major silting at 1K and 113k to 115k. Minor silting elsewhere. Major scouring and sand silting at 50 to 53K and 54k to 58K Washout of shoulder from 0k to 1.5k No flood damage Major damages at 0.7k to 2.7k and 15.05k to 15.15k Damages of floodways at 0.8k,1.1k and 1.15k 497, , , , , , , , ,980, GST 498, Total including GST 5,478, Page 4 of 29

5 3. Flood Damage per Road 3.1. Yuendumu - Nyirripi Road Road Name: Yuendumu - Nyirripi Road Road length:150km Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount from To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst ($) Scouring and washout on carriageway Minor Ext C , Scouring and washout on carriageway Moderate Ext B , Scouring and washout on carriageway Major Ext A , Floodway wash out Major Ext Fld , Floodway wash out Major Ext Fld , Scouring and washout on carriageway Moderate Ext B , Floodway wash out Major Ext Fld , Scouring and washout on carriageway Minor Ext C , Scouring and washout on carriageway Minor Ext C , Scouring and washout on carriageway Major Ext A , Floodway wash out Major Ext Fld , Scouring and washout on carriageway Minor MN , Floodway wash out Major MJ , Scouring and washout on carriageway Minor MN , Scouring and washout on carriageway Moderate MD , Scouring and washout on carriageway Minor MN , Scouring and washout on carriageway Moderate MD , Scouring and washout on carriageway Minor MN , Total road length requiring repairs 52.3 Reinstatement of offlet drains Ongoing costs Mobilisation/demobilisation (incl contractor) Soil and Pavement Testing Drilling bore CLC gravel royalties Traffic Mgt cost Environmental cost Total Roadworks Project management 5% Overheads 10% Construction contingency 5% Total cost for flood damage repair to Yuendumu - Nyirripi Road 3.2. Yuendumu-Yuelamu Road Road Name: Yuendumu-Yuelumu Road From Chainage To Repair Strategy Length (Km) Area Rate 170, , , , , , , , ,934, , , , ,321, Amount ($) ex gst (m 2 ) ($/m 2 ) Silting of sand thoughout carriageway Moderate MD , Silting of sand thoughout carriageway Moderate MD , Silting of sand on carriageway Minor MN , Silting of sand thoughout carriageway Moderate MD , scouring of sides of the carriageway Minor MN , Floodway-washout Major MJ , Silting of sand thoughout carriageway Major MJ , Silting of sand thoughout carriageway Major MJ , Silting of sand thoughout carriageway Minor MN , Reinstatement of offlet drains CLC royalties Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% Nature of dmage Severity of damage Road length:42km Flood damage repair 15, , , , , , , , , , Total cost for flood damage repair to Yuendumu - Yuelamu road 497, Page 5 of 29

6 3.3 Yuelamu-Ten Mile Road Road Name: Yuelamu-Ten Mile Rd Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount From To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst ($) Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Minor MN , Floodway washout Minor MN , Scouring on carriageway Moderate MD , Scouring and Silting of sand on carriageway Moderate MD , Scouring on carriageway Major MJ , Scouring on carriageway Minor MN , Scouring and Silting of sand on carriageway Major MJ , Scouring and silting of sand on carriageway Moderate MD , Scouring and silting of sand on carriageway Major MJ , Scouring and silting of sand on carriageway Moderate MD , Reinstate of offlets 29, CLC royalties 43, Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% Total cost for flood damage repair to Yuelamu - Ten Mile road Road length:31km 495, , , , , , , , , Page 6 of 29

7 3.4 Ten Mile-Pulardi-Tanami Road Road Name: Ten Mile-Pulardi-Tanami Rd (Council controlled section) Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount From To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst ($) 0 0 to 0.6 Scouring of carriageway Moderate MD , Scouring of carriageway Major MJ , Roadway Scouring and silting of sand in one side Minor MN , Roadway Scouring and silting of sand in one side Moderate MD , Roadway Scouring and silting of sand in one side Minor MN , Roadway Scouring and silting of sand in one side Major MJ , Roadway Scouring and silting of sand in one side Moderate MD , Roadway Scouring and silting of sand in one side Major MJ , Roadway Scouring and silting of sand in one side Moderate MD , Roadway Scouring and silting of sand in one side Minor MN , Roadway Scouring and silting of sand in one side Moderate MD , Roadway Scouring and silting of sand in one side Minor MN , Reinstate of offlets 13, CLC royalties 36, Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% Total cost for flood damage repairto Ten Mile - Pulardi - Tanami Road Road length:20km 314, , , , , , , , , Mt Dennison Willowra backroad Road Name: Mt Dennison - Willowra backroad From Chainage To Nature of dmage Severity of damage Road length:115km Repair Strategy length (Km) Flood damage repair Area Rate Amount ($) ex gst (m 2 ) ($/m 2 ) Floodway silting Major MJ , Silting on carriageway Minor MN , Silting on carriageway Minor MN , Silting on carriageway Minor MN , Silting on carriageway Minor MN , Floodway silting Minor MN , Floodway silting Minor MN , Silting on carriageway Minor MN , Silting on carriageway Minor MN , Floodway silting Minor MN , Floodway silting Minor MN , Silting on carriageway Minor MN , Silting on carriageway Minor MN , Floodway silting Major MJ , Floodway silting Major MJ , Reinstate of offlets CLC royalties Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% Total cost for flood damage repair to Mt Dennison - Willowra backroad 10, , , , , , , , , , , Page 7 of 29

8 3.6. Yuen/Nyir Road - Mt Wedge Papunya Road (Council controlled section) Road Name: Yuen/Nyir road - Mt Wedge - Papunya Rd (Council controlled section) From Chainage To Nature of dmage Severity of damage Road length :65Km Repair Strategy length (Km) Flood damage repair Area (m 2 ) Rate ($/m 2 ) Amount ($) ex gst Silting and scouring on carriageway Minor MN , Silting and scouring on carriageway Minor MN , Silting and scouring on carriageway Minor MN , Silting and scouring on carriageway Minor MN , Silting and scouring on carriageway Minor MN , Silting on carriageway Minor MN , Major sand silting and scouring on carriageway Major MJ , Floodway washout Major MJ , Major sand silting and scouring on carriageway Major MJ , Floodway washout Minor MN , Floodway washout Minor MN , Scouring on carriageway Major MJ , Scouring and silting on Carriageway Moderate MD , Major scouring on carriageway Major MJ , Scouring and silting on Carriageway Moderate MD , Scouring and silting on Carriageway Minor MN , Reinstate of offlets 17, CLC royalties Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% 52, , , , , , , , , Total cost for flood damage repair to Yuendumu/Nyirripi road - Mt Wedge - Papunya Rd (CDRC section) 484, Ti Tree Station (Nturiya) Access Road Road Name: Ti Tree Station (Nturiya) Access Rd Road length:15km Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount ($) From To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst Reconstruct floodway Major MJ , Reinstate Offlets Reconstruct floodway Major MJ , Reconstruct floodway Major MJ , Reinstate Catch Drain Reformation Moderate MD , Reinstate Gravel Major MJ , Reformation Minor MN , Reconstruct floodway Major MJ , Reinstate of offlets 19, CLC royalties 15, Total Roadworks 206, Mobilisation demobiliation cost 30, Traffic Mgt cost 2, Environmental cost 1, Sub total 240, Project management 5% 12, Overheads 10% 24, Construction contingency 5% 12, Total cost for flood damage repair to Ti Tree Station (Nturiya) access road 288, Page 8 of 29

9 3.8. Engawala Access Creek Crossing Road Name: Engawala Access Creek Crossing Road length:1.2km Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount From To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst ($) Reconstruct floodway Major MJ , Reconstruct floodway Major Concrete , Reconstruct floodway Major MJ , Reconstruct floodway Major MJ , Reconstruct floodway Major MJ , Reconstruct floodway Major MJ , Reinstate offlets 8 numbers 4, CLC royalties 4, Total Roadworks Mobilisation demobiliation cost Traffic Mgt cost Environmental cost Sub total Project management 5% Overheads 10% Construction contingency 5% Total cost for flood damage repair to Engawala Access Creek Crossing 47, , , , , , , , , Yuendumu internal roads-sealed section Road Name: Yuendumu internal road-sealed section Road length:1.5km Chainage Flood damage repair Severity of Nature of dmage Repair Area Rate Amount from To damage length (Km) Strategy (m 2 ) ($/m 2 ) ex gst ($) Scouring and washout on shoulder Moderate MDS , Ongoing cost ClC royalties 5, , Traffic Management cost Environmental cost Total cost to reinstate flood damage repair on Yuendumu internal road shoulders 1, , Page 9 of 29

10 4. Repair strategies All descriptions based on NT Department of Infrastructure 2014/15 Standard Specification for road maintenance 4.1 Repair of Major Damage-(MJ). By Council Road Crew 57.6k-Mt Wedge road 51.2K Mt Wedge Major damages include scouring or/and siltation over 500mm deep on road surface and floodways. Rectification method as follows: Clearing of unwanted material: Removal of unsuitable material such as silt, rubble, sand, loose material, and debris dumped on flood ways, roadway and drains by flood. Mostly graded over windrows. Refilling and Reformation: This includes hauling, placing, watering and compacting material on all prepared areas including scours and washouts. Refilling includes filling holes and other depressions on roadway and floodway. Spread material in uniform level layers to a maximum thickness of 250mm layers and compact to required degree of compaction. Shape grade and compact road generally with material to reform surface. Compaction: Mix to homogeneous material and compact to required degree using suitable static/vibration roller. Based on distance of 1Km; pavement width 6 m Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x Fuel/water trailer x Caravan x Loader x Water cart x Roller 10T x Excavator x1 (borrow pit) Truck gravel 10T x Work supervisor Cost($/m 2 ) Page 10 of 29

11 4.2 Repair of Moderate Damage-(MD). By Council Road Crew 6.4K-Ten Mile to Pulardi 50.9K Yuen/Nyirripi to Papunya Moderate Damage includes scouring and/or siltation from 150mm to 500mm deep on road surface and floodway. Proposed rectification method as follows: Clearing: Removal of unsuitable material such as silt, rubble, sand and debris dumped on flood ways, roadway and drains by flood. Refilling /cut back and reformation: This includes hauling, placing and compacting material on all prepared areas including scours and washouts, holes and depressions. Depending on the circumstances, either refilling or cut back the existing uneven surface will apply until reach sound dense surface. Compaction: Compact to required degree using suitable static/vibration roller. Based on distance of 1Km; pavement width 6 m Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x Fuel/water trailer x Caravan x Loader x Water cart x Roller 10T x Excavator x1 (borrow pit) Truck gravel 10T x1 Work supervisor Cost($/m 2 ) Page 11 of 29

12 4.3 Repairing of Minor Damage (MN). By Council Road Crew 23.7k Yuendumu-Yuelamu Road 27.7k Pulardi road Minor Damages classified as scouring or/and siltation up to 150mm deep on road surface and floodways. Proposed rectification method as follows: Surface reformation: Removal of unsuitable material such as sand and debris dumped on flood ways and roadway. Shape grade and compact road generally with material cut from higher ground alongside the road if suitable. As necessary cut back existing uneven surface to reach sound dense surface while achieving surface formation. Use suitable static/vibration roller for compaction with sufficient roller passes. Based on distance of 1Km; pavement width 6 m Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x Fuel/water trailer x Water cart x Roller 10T x Caravan x Work supervisor Cost($/m 2 ) 1.74 Page 12 of 29

13 4.4 Repair of Major Damage to Floodways-(MJ). By Council Road Crew 20.0K-Yuel-Tanami Road 51.2k Mt Wedge to Papunya Rd Clearing: Removal of unsuitable material such as silt, rubble, sand and debris dumped on flood way out to levee bank. Reform: Reconstruct floodway with gravel lifts to flow level. Maintain additional 2m width of carriageway on either side of floodway. Compact to required degree of compaction on each layer. Use suitable static/vibration roller for compaction with sufficient roller passes. Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x Fuel/water trailer x Caravan x Loader x Water cart x Roller 10T x Excavator x1 (borrow pit) Truck gravel 10T x Work supervisor Cost($/m 2 ) Page 13 of 29

14 4.5 Reinstatement of offlet drains. By Council Road Crew Clearing: Remove/clear all obstructions including sand silt, trees, fallen branches and rocks, etc. Reconstruction: Trim to shape of trapezoidal drain with batter slope 1:2. Align and grade offlet so that water drains away without scour and damaging the road, and to disperse water as sheet flow or into natural water courses at a gradient not to exceed 1:40(1.5%). Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x1 Cost/offlet($) Reinstatement of shoulders at Yuendumu sealed section. By Council Road Crew Clearing: Removal of unsuitable material such as silt, rubble, sand and debris dumped alongside the shoulders. Scarifying/Refilling: Damaged surface shall scarify to ensure proper bonding of filling material. Suitable shoulder material will be placed on scarified surface to reach the original level. Compaction: Compact with no compaction plane and free of cracking to confirm the required degree of compaction. Use suitable static/vibration roller for compaction with sufficient roller passes. Resources Qty Rate($/hr) hrs Amount($) Grader x Service truck x Fuel/water trailer x Loader x Water cart x Roller 4T x Excavator x1 (borrow pit) Truck gravel 10T x1 Work supervisor Cost/m 2 ($) Page 14 of 29

15 4.7 Road Repairs. By Contractor. Method A Earthworks + Sub grade+ Gravel base Reinststement of formation and gravel pavement from scouring damage 150mm gravel base 150mm subgrade work 150mm earth work` Rate for 1m2 $ 12 Method B Earthworks + Subgrade Earthworks and Sub Grade damaged by severe scouring 150mm sub grade formation 150mm earth work` Rate for 1m2 $ 8 Method C Formation reinstatement Formation damaged by scouring and siltation from runoff 150mm earth work` Rate for 1m2 $ 4 Page 15 of 29

16 APPENDIX A - RAINFALL ACROSS CENTRAL DESERT REGIONAL COUNCIL AREA Rainfall (mm) Dec 2014 Rainfall (mm) Jan 2015 Lajamanu Rabbit Flat Yuendumu Kintore Watarrka Ti-Tree Alice Springs Arltunga Jervois 1 Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan Dec Jan TOTAL TOTAL Average Average Month Month Annual Annual Data from Bureau of Meteorology website Blank cells = no data Kintore = Wulungurru; Ti Tree = Territory Grape Farm; Watarrka = Kings Canyon Papunya and Ali Curung had no observations during December and January Lajamanu Rabbit Flat Yuendumu Kintore Watarrka Ti-Tree Alice Springs Arltunga Jervois Nyirripi Engawala Page 16 of 29

17 APPENDIX B Council Road Map Mt Dennison Willowra backroad Tanami Rd Stuart Hwy Nturiya Access Rd Yuel Access Rd Yuen Nyir Rd Yuen-Papunya backroad Stuart Hwy Council boundary Tanami Rd

18 APPENDIX C- Photographs 1. Yuendumu-Nyirripi road 5.1K 6.5K

19 61.8K 62K Page 19 of 29

20 2. Yuendumu-Yuelamu road 23K 27K Page 20 of 29

21 3. Yuelamu-Ten Mile Road 20K 25K Page 21 of 29

22 26K 30K Page 22 of 29

23 4. Ten Mile - Pulardi Tanami Rd 1K 6K Page 23 of 29

24 5. Yuen/Nyir Road - Mt Wedge Papunya Rd (Council controlled section) 51K 50K Page 24 of 29

25 54K 57K Page 25 of 29

26 6. Mt Dennison Willowra backroad 106K 114K Page 26 of 29

27 7. Yuendumu road-sealed section 8. Ti Tree Station Access road Page 27 of 29

28 9. Engawala Access Creek Crossing Page 28 of 29

29 CLC Royalties Appendix D- CLC Gravel Extraction Royalties Expected CLC rate for gravel excavation =$10/m3. Following gravel is required for each road: Road Length (Km) volume (m 3 ) Amount ($) Yuendumu-Yuelamu-300mm , Yuelamu-Ten Mile , Ten Mile - Pulardi-Tanami Rd , Yuen/Nyirripi - Mt Wedge - Papunya (Council section) , Mt Dennison - Willowra , Yuendumu - Nyirripi (150mm) Yuendumu-Nyirripi (300mm) Yuendumu road sealed section shoulder reinstate Ti Tree Station (Nturiya) access (300mm) Engawala Access Creek Crossing (300mm) Total CLC Gravel Extraction Royalties , , , , , , Page 29 of 29