Source
https://www.qldc.govt.nz/media/lz3be45f/housing-infrastructure-fund-dbc-ladies-mile-12072018.pdf — original source (opens in a new tab; the file is not redistributed)
Ladies Mile Detailed Business Case Estimate (2018) — NZ civil earthworks + buried-pipe rate card (OT_113)
A signed, NZTA-accepted NZ civil unit-rate card — and the primary that corrects CR_050's watermain figure
The June-2018 Detailed Business Case Estimate for the Ladies Mile enabling works (QLDC Housing Infrastructure Fund, SH6 Queenstown), covering transport + three-waters with **line-item
/m,/m³ and/m² rates** (ex-GST, ex-escalation), prepared with parallel **Opus** and **WTP** estimate columns and **accepted by NZTA**. It serves two Neobiome Intelligence purposes at once: (a) a **bulk-earthworks + installed-pipe rate card** that brackets the micro-hydro penstock distance-cost term (D26/RT_286), and (b) it **corrects a mis-attribution in [[cr_050_nz-offgrid-infrastructure-cost-reference|CR_050]]** — the "1,600–2,500/m 100 mm watermain” CR_050 cited is in fact this estimate’s 1050 mm RCRRJ stormwater pipe rate; the real watermain supply+lay rate is $200–350/m (DN315–355 PE100).data_quality: verified— every figure read verbatim from the signed primary via pdftotext.
Summary
The Detailed Business Case Estimate (DBE) for the Ladies Mile growth-area enabling infrastructure (Queenstown Lakes District Council, Housing Infrastructure Fund; SH6 corridor near Lake Hayes Estate), dated June 2018 and accepted by NZ Transport Agency (Waka Kotahi). It is a 12-page quantity-surveyor cost estimate (Excel exported to PDF) covering transport (roundabout, pavements, footpaths, an underpass, road lighting) and three-waters (watermains, wastewater pressure pipe, stormwater), with each activity carried at a Base Estimate, a P50 (base + 30% contingency) and a P95 (funding-risk) level, and two parallel estimate columns — “Opus Estimate” (Opus International Consultants’ original design cost) and “WTP Review” (a re-estimate by the DBE preparers). All rates are NZ$ per metre / m³ / m², exclusive of GST and escalation.
Its value to NI is two-fold: (1) it brackets the micro-hydro penstock distance-cost term (D26 / RT_286) with NZTA-accepted evidence — a bulk-earthworks trench floor and an installed-pipe ceiling that the engine’s live 110/m** sits comfortably inside; and (2) it **corrects [[cr_050_nz-offgrid-infrastructure-cost-reference|CR_050]]'s water-reticulation `/m`, whose “100 mm HDPE main ~1,600–2,500/m" is a mislabelled quotation of this estimate's 1050 mm RCRRJ stormwater rate — the true watermain rate is 200–350/m supply+weld+lay.
Key claims
- claim: "DOCUMENT IDENTITY & TERMS. 'Ladies Mile' Detailed Business Case Estimate (LM Cost Estimate v1.6-27.5.2018), Document Set ID 5953262, date of estimate June 2018, Cost Index (Qtr/Year) '1st 28'. Prepared by M J Revis (WTP/WTPi), internal peer review H A McCondach (WTP/WTPi), external peer review 'Signed', 'Estimate accepted by NZTA — Signed'. Two estimate columns run side by side: 'Opus Estimate' (Opus International Consultants, original design cost estimate) and 'WTP Review' (DBE re-estimate). P50 = base + 30% contingency. Every sheet: 'These estimates are exclusive of escalation and GST.' 3-Waters Project Base Estimate $10,402,029; Project Expected Estimate (P50) $13,012,638 (incl. Country Club stormwater cost-share $1,700,000). All-activities base estimate $19,830,536; P50 (all activities) $25,269,697."
source_location: "p.1–3 DBE summary sheets ('Project Estimate — Total' / 'Project Estimate — 3 Waters'); page footers (Document Set ID 5953262, v1 10/12/2018)"
- claim: "BULK EARTHWORKS & EXCAVATION unit rates (NZ$/m³ except where noted). Transport works (p.7): Topsoil stripping 200 mm to waste $50/m³; Cut & undercut to waste $50/m³; Granular bulk fill $50/m³; Sawcut existing kerb & seal $15/m; Clearing of site $20,000 LS. Underpass works (p.11): Excavate & dispose off site to reduced level (all materials) $50/m³; Extra-over cost for excavation in ROCK $130/m³ (PROVISIONAL); Undercut unsuitable material & dispose $90/m³; AP65 in undercut areas $95/m³; Earthwork support (sheet piles) $600/m². (The $50/m³ bulk-excavation and $130/m³ rock EO rates set the trench-only floor for any buried linear infrastructure.)"
source_location: "p.7 of 12 (Transport, EARTHWORKS); p.11 of 12 (Underpass, EARTHWORKS)"
- claim: "WATERMAIN PE100 PRESSURE-PIPE rates — 'supply, weld and lay … PE100 PN12.5 … (includes all valves and fittings)': DN315 rising main — Opus 3340 m @ $350/m = $1,169,000; WTP 2030 m @ $200/m = $406,000. DN315 falling main — WTP 560 m @ $300/m = $168,000. DN355 falling main — WTP 750 m @ $350/m = $262,500. Supply+weld+lay band = $200–350/m (ex-GST, June 2018). THE SMALLEST PRESSURE WATERMAIN IS DN315 (315 mm) — there is NO 100 mm watermain anywhere in this estimate. Ancillary: sluice valves (1 per 100 m) $2,500 ea; bends $1,000 ea; blank ends $1,400 ea; pressure testing 3340 m @ $6/m; access track $55/m. Watermain Installation total (incl. 2×1000 m³ steel reservoirs @ $300–400k ea): Opus $2,019,000 / WTP base $2,049,540 / P50 $2,664,402 → derived all-in ~$614/m base, ~$798/m P50 over 3340 m."
source_location: "p.4 of 12 (3-Waters, Watermain Installation)"
- claim: "WASTEWATER PE100 PRESSURE-PIPE rates: DN225 pressure pipe — Opus 1720 m @ $360/m = $619,200; WTP 1720 m @ $275/m = $473,000. DN160 pressure pipe — Opus 750 m @ $280/m = $210,000; WTP 750 m @ $200/m = $150,000. Air valves assumed every 500 m; scour valves every 2,000 m. The smallest pressure pipe anywhere in the estimate is DN160 (160 mm) @ $200–280/m — still not 100 mm, and still roughly 6–8× below the $1,600/m rate CR_050 mis-cited."
source_location: "p.4 of 12 (3-Waters, Waste water Installation)"
- claim: "STORMWATER (reinforced-concrete rubber-ring-joint, RCRRJ) rates — THE ACTUAL SOURCE OF THE '$1,600–2,500/m' FIGURE: 1050 mm RCRRJ — Opus 150 m @ $1,600/m = $240,000; WTP 150 m @ $2,500/m = $375,000. 525 mm RCRRJ — 220 m @ $950/m = $209,000 (both columns). These are large-diameter GRAVITY STORMWATER concrete pipes, NOT pressure watermains. Gravity PVC-U SN8 drainage (p.7): 750 mm $800/m; 600 mm $650/m; 225 mm $300/m; NZTA-F2 110 mm subsoil drain (incl. bedding, filter, geotextile, cleaning eye) $60/m; NZTA-F2 subsoil drain elsewhere $25/m (WTP) to $65/m (Underpass)."
source_location: "p.5 of 12 (3-Waters, Stormwater Installation, RCRRJ); p.7 of 12 (Transport, DRAINAGE)"
- claim: "THE CR_050 MIS-ATTRIBUTION, IDENTIFIED AND CORRECTED. [[cr_050_nz-offgrid-infrastructure-cost-reference|CR_050]] recorded for its water `reticulation` $/m line (AF-16 / RT_313): '100 mm HDPE main ~$1,600–2,500/m installed (QLDC/Opus Ladies Mile DBC estimate)'. Reading the primary verbatim, this is wrong on three counts: (1) wrong diameter — there is no 100 mm watermain (smallest pressure watermain DN315; smallest pressure pipe of any kind DN160); (2) wrong pipe class — the $1,600 (Opus) / $2,500 (WTP) numbers are the 1050 mm RCRRJ STORMWATER pipe rate (p.5); (3) wrong magnitude — the real watermain supply+weld+lay rate is $200–350/m (DN315–355 PE100 PN12.5), all-in ~$614/m base / ~$798/m P50. This is the 'right document, wrong line' failure mode the project flagged as feedback_cr_verified_source_only. The CR_050 $1,600–2,500/m band must be STRUCK and replaced with $200–350/m supply+lay (all-in ~$600–800/m)."
source_location: "p.4 (watermain $200–350/m) vs p.5 (1050 RCRRJ $1,600/$2,500) of 12; cross-ref CR_050 AF-16 / RT_313"
- claim: "PROJECT CONTEXT LINES (ex-GST, ex-escalation): Physical-works 'Earthworks' line $948,445 base; 'Conveyance Pipelines' line $3,914,150 base (30% contingency $1,174,245). Road-lighting 'Power Cable Installation (incl. trenching and ducting if required)' $10,000 LS. Ladies Mile is a large greenfield GROWTH-AREA TRUNK scheme (DN315–355 rising/falling mains feeding 2×1000 m³ reservoirs, pumped) — not a small remote-community reticulation network; its rates are an UPPER-BOUND anchor for community-scale distribution main."
source_location: "p.2 of 12 (Project Estimate — Total, Physical Works items 2 & 6); p.8 of 12 (Transport, ROAD LIGHTING); p.4 (reservoirs)"Neobiome Intelligence relevance
This one signed primary lands on three NI surfaces — the micro-hydro penstock term, the D03 water-reticulation cost card (where it corrects CR_050), and any distance-linear energy CapEx.
micro_hydro — penstock distance term (D26 / RT_286). The NI micro-hydro cost is a base machine/intake /kW (the engine's `micro_hydro` base 19k/kW) plus a distance-linear penstock term (stream_distance × $/m), where trench/earthworks is the dominant component. This NZTA-accepted card brackets that term with primary NZ evidence:
- Trench-only floor — bulk excavation
50/m³ + rock EO130/m³ implies roughly $20–65/m for a ~0.4–0.5 m³/m open-cut penstock trench (inference, not a source figure; excludes bedding, backfill, laying labour, reinstatement, so a floor). - Installed-pipe ceiling — buried welded PE100 pressure main “supply, weld and lay incl. all valves and fittings” at $200–360/m (DN160–DN355) is the fittings-heavy upper analogue (a continuous penstock carries fewer valves/fittings than a reticulated main).
The engine’s current hydro_penstock_capex_per_m = 110/m** (`params.py`, "sourced/medium": URL_018 PE100 pipe 8–13/m + CR_037/CR_027 trench 80–140/m; RT_286) sits **comfortably inside** this NZTA bracket — so the card **corroborates the live 110/m, lifting the trench component from corpus-anchored proxies to a published, NZTA-accepted unit rate. The one open item this source does not settle is the base-vs-distance double-count (whether the $19k/kW base already embeds a typical penstock) — that stays the open D26 / RT_286 model-design decision.
D03 Water, Waste & Circular — reticulation $/m card, and a CR_050 correction. This is the primary behind CR_050’s water-reticulation firming (RT_313 / AF-16), and reading it verbatim corrects CR_050:
Water $/m reading | CR_050 (as recorded) | This primary (verbatim) |
|---|---|---|
| “Watermain” pipe supply+lay | $1,600–2,500/m (labelled “100 mm HDPE”) | $200–350/m (DN315–355 PE100 PN12.5) |
| All-in main + valves + reservoir | — | ~614/m base, ~798/m P50 (over 3340 m) |
| True owner of “$1,600–2,500/m” | (claimed watermain) | 1050 mm RCRRJ stormwater pipe |
| Smallest pressure pipe present | — | DN160 wastewater @ $200–280/m |
It also supplies a diameter-resolved supply-and-lay card for the D22 water-cascade reticulation/backstop mains: PE100 pressure main 200–360/m**, gravity PVC-U SN8 **300/m (225 mm) → 650/m (600 mm) → 800/m (750 mm), RCRRJ stormwater 950/m (525 mm) / 1,600–2,500/m (1050 mm), NZTA-F2 110 mm subsoil drain **60/m** — complementing [[cr_032_nz-water-backstop-costs-2026|CR_032]]'s ~250–400/m mains-extension figure with a diameter-resolved supply-and-lay basis. Caveat: Ladies Mile is a large trunk scheme (DN315–355 mains, 2×1000 m³ reservoirs) — a remote community would use cheaper 100–150 mm distribution main, which this DBC does not price; so these are an upper bound, and the small-diameter community rate stays an open gap.
D01 Renewable Energy & Storage — distance-linear CapEx cross-check. Any distance-linear energy CapEx term (grid line-extension, LV reticulation, penstock) shares the same trench-cost driver. This card supplies NZTA-accepted inputs — bulk excavation 50/m³**, rock **130/m³, installed buried pressure pipe $200–360/m, and a ‘Power Cable Installation incl. trenching & ducting’ line — that cross-check the CR_037/CR_027 line-cost proxies the engine uses for those terms.
Use caveats (carry into any calculation): (1) 2018 estimate, exclusive of escalation — apply a 2018→2026 NZ construction-cost escalation before using any rate directly. (2) Exclusive of GST. (3) Opus vs WTP spread — competing columns disagree by 30–75% on several lines (DN315 350 vs 200/m; 1050 RCRRJ 1,600 vs 2,500/m), so treat any single rate as ±30–75%. (4) Urban-roading context — traffic-management and service-congestion loading may overstate a rural greenfield penstock trench; but hill-terrain micro-hydro sites carry the rock-excavation risk ($130/m³ EO) this card also prices.
Research targets
Documents to retrieve
- A current (2025/26) general NZ civil rate card — Rawlinsons NZ Construction Handbook (library/paywalled) or an EDB/council schedule-of-rates (Watercare / Network Tasman civil unit rates) — to replace this project-specific 2018 estimate with a live, general-purpose card (residual on both RT_292 and RT_317; the Ladies Mile DBE substantially firms the trench + watermain rates but is a single-project, dated estimate).
Research gaps
- NZ construction-cost escalation 2018→2026 (RT_368). These rates are explicitly exclusive of escalation; using them at 2026 requires an escalation factor (Stats NZ Capital Goods Price Index — civil construction, or the Rawlinsons/NZIER construction cost index). Needed before any OT_113 rate enters the engine. (RT_368 — raised from RT_292’s civil-rate framing. Advanced 2026-07-20: the escalation series is now retrieved — RD_032, Stats NZ CGPI civil construction
CEPQ.S61103, base Sep-2022=1000, Mar-2026 = 1101 / +3.1% YoY; the multiplier itself still awaits the Jun-2018 Infoshare datum, so RT_368 stays open.) - **Small-diameter (100–150 mm) community reticulation main
/m (RT_369).** This DBC prices only 315–355 mm trunk main; a small remote-community distribution main (100–150 mm PE100)/m installed is still unquantified — the RT_313 residual after the trunk-main upper bound is set here. (RT_369 — raised from RT_317’s reticulation framing.) - Base-vs-distance split for micro-hydro CapEx (existing D26 / RT_286). Whether the base
micro_hydro$19k/kW already embeds a typical penstock/earthworks (double-count risk) — unchanged by this source; still the open model-design decision. - Data correction (CR_050, action not RT): strike CR_050’s “100 mm HDPE main ~
1,600–2,500/m installed" and replace with the verified reading (200–350/m supply+lay; all-in ~600–800/m; the1,600–2,500 is the 1050 mm RCRRJ stormwater rate). Apply on the CR_050 page + the D03 evidence line; the model-side correction is flagged.
Resolved
- RT_292 (RESOLVED → this page): published NZ earthworks/trenching unit rate to firm the dominant trench component of the micro-hydro penstock term — retrieved and read verbatim.
- RT_317 (RESOLVED → this page): the QLDC/Opus Ladies Mile DBC behind CR_050’s watermain figure — retrieved; refutes and corrects the mis-attributed $1,600–2,500/m band.
Notes
Single signed primary: the Ladies Mile DBE (sha256 f7c15f60…, Document Set ID 5953262, 1,081,085 bytes). This page carries both analytical framings: the civil-rate/penstock card (RT_292) and the CR_050 watermain refutation (RT_317). Read verbatim via pdftotext -layout, figure-by-figure verified → data_quality: verified. url blank — no confirmed public URL captured; obtained via QLDC HIF records. All figures ex-GST, exclusive of escalation, June 2018 cost base — apply CPI/CGPI to 2026 before use. Cross-linked from CR_050 (correction), CR_037 / CR_027 (penstock trench proxies), and the micro-hydro / D26 model-design thread (RT_286).
Connections
Links to
Referenced by
Sources (5): CR_050 · CR_054 · LIT_074 · OT_128 · RD_032
EDT domains (2): D01: Renewable Energy & Storage Systems · D03: Water, Waste & Circular Systems
Technologies (1): Micro-hydro (run-of-river, community-scale)