CAPEX, OPEX, lifecycle cost, and unit cost — tied directly to the hydraulic model.
The ConduitNET Water Supply Cost Model is a physics-based, bottom-up cost framework for water supply infrastructure. It reads hydraulic model structure and results, applies location-aware economic parameters, and computes capital, operating, lifecycle, and unit water costs.
Three cost layers are computed together.
ConduitNET evaluates the economic consequences of a water distribution design across capital cost, operating cost, and lifecycle cost. These are not separate spreadsheets; they are linked to the same EPANET-based network model, operating patterns, and project location.
CAPEX — capital cost
- Pipes: material, installation, trenching, fittings, reinstatement
- Pump stations: equipment, motors, civil works
- Tanks and storage: structural quantities and site works
- Valves, appurtenances, land, engineering, contingency
OPEX — operating cost
- Pumping energy from flow, head, efficiency, and operating time
- Grid electricity, solar, or hybrid energy scenarios
- Maintenance, replacements, and recurring assumptions where included
- Raw-water purchase or abstraction cost when applicable
Lifecycle cost
- Present value of capital and future operating costs
- Design life and discount/interest-rate assumptions
- Equipment replacements such as batteries or inverters
- Unit cost of water from annualized cost and production volume
Cost is part of the design loop.
Pipe size changes headloss. Headloss changes pump energy. Pump energy changes lifecycle cost. Lifecycle cost feeds back into optimal pipe sizing, storage, and operations. ConduitNET makes that feedback visible immediately.
Cost is computed from the network model, not entered as a disconnected estimate.
Network geometry
Pipe lengths, diameters, node coordinates, elevations, tank geometry, pump links, and valves define the physical system.
Hydraulic results
Flow, head, pressure, pump head, pump flow, tank behavior, and demand patterns drive power, capacity, and operating cost.
Project context
Georeferenced location, selected region, material, site condition, energy source, land class, and user overrides define the economic context.
ConduitNET converts hydraulic model inputs into quantities, then converts quantities into cost.
The cost estimate is not a disconnected spreadsheet. It is computed from the EPANET / ConduitNET network model, hydraulic results, regional economic presets, and user-controlled assumptions. Users can see what comes from the model and what can be customized.
The costing chain
Network input → hydraulic result → derived physical quantity → regional unit price → CAPEX, OPEX, lifecycle, and unit-water-cost output.
| ConduitNET / EPANET input | Derived quantity | Cost impact | User can refine |
|---|---|---|---|
| Pipe length, diameter, material, route geometry | Pipe material mass, trench length, trench volume, bedding/backfill volume | Pipe CAPEX, excavation, bedding, reinstatement, installation labor | Pipe material, cover depth, soil class, trench width, road restoration class |
| Node elevations, pressures, demands, operating patterns | Required hydraulic grade and delivered volume | Service adequacy, pump sizing, operating cost, unit cost of delivered water | Demand scenarios, service pressure, peaking factors, operating schedule |
| Pump curves, pump links, flow, head | Hydraulic power, motor size, annual energy use | Pump station CAPEX, grid/solar/hybrid OPEX, lifecycle energy cost | Pump efficiency, VFD/motor efficiency, tariff, solar assumptions, operating hours |
| Tank volume, geometry, elevation / staging height | Structural quantities, support demand, hydraulic grade contribution | Tank CAPEX, foundation/support, seismic/wind cost, pumping energy interaction | Tank type, height, material, seismic zone, foundation type, site condition |
| Buried / underground storage geometry and burial depth | Excavation depth, slab/wall/roof quantities, uplift/buoyancy demand | UST CAPEX, excavation, dewatering risk, waterproofing, backfill, surface restoration | Burial depth, groundwater condition, soil/rock class, structural assumptions, reinstatement |
| Valves, fittings, meters, appurtenances | Component counts and size-based quantities | Installed appurtenance CAPEX, maintenance allowances | Valve spacing, fitting factors, supplier quotes, project standards |
| Georeferenced location / selected region | Labor rate, material prices, electricity tariff, solar resource, seismic context | Regional CAPEX, energy OPEX, solar sizing, lifecycle economics | Preset region, local unit prices, utility rate, contractor bid data |
| Financial assumptions | Annualized cost, present value, replacement cycles | LCC and unit cost per m³ of delivered water | Design life, discount/interest rate, contingency, E&A, replacement intervals |
Intelligent defaults
ConduitNET starts with region-aware assumptions for labor, materials, construction conditions, electricity, solar, seismic context, contingency, design life, and standard component factors so early planning estimates can be generated immediately.
Customizable assumptions
Users can progressively replace defaults with local quotes, utility bills, route surveys, geotechnical data, tank supplier data, pump curves, contractor pricing, and agency-specific lifecycle assumptions.
Bottom-up engineering quantities drive cost.
The model computes physical quantities first, then prices them with regional economic parameters. This is why the same hydraulic system can be compared across countries, states, and project contexts.
Pipes
Pipe material cost is based on diameter, wall thickness, material density, and length. Wall thickness is related to design pressure and material strength.
t = P D / (2σ / SF)
Trenching is computed from cover depth, pipe outside diameter, bedding, trench width, soil class, water table, and surface reinstatement.
Pumps
Pump capital and operating costs are linked to hydraulic power from EPANET flow and head conditions.
P = ρ g Q H / η
Efficiency assumptions, motor/VFD performance, pump curves, operating hours, and energy tariffs determine lifecycle energy cost.
Tanks and storage
Tank costs are based on storage volume, geometry, elevation, structural quantities, material assumptions, seismic zone, foundation/site context, and tank type.
Elevated tanks, ground tanks, covered storage, underground storage, and other storage forms have different structural and lifecycle implications.
Valves, fittings, and appurtenances
Valves, fittings, thrust restraint, meters, special components, and project-specific additions can be included through explicit components or multipliers.
Civil works and land
Excavation, bedding, backfill, compaction, pavement restoration, land classification, easements, and site development can dominate costs in urban or difficult settings.
Operating cost is derived from hydraulic work over time.
EPANET provides time-varying network behavior through demand, head, and operational patterns. ConduitNET uses that hydraulic behavior to compute pumping power and lifecycle energy cost.
Grid energy
Energy cost is computed from pump power, operating duration, pump/motor/VFD efficiency, and regional electricity tariff.
Energy cost = kWh × $/kWh
Solar pumping
Solar sizing uses daily energy demand, regional peak sun hours, system efficiency, degradation, inverter losses, wiring losses, dust, and temperature effects.
kWp = daily kWh / (sun hours × efficiency × degradation)
Battery autonomy
Battery capacity is sized from pump power and required autonomy hours, with depth-of-discharge and round-trip efficiency assumptions.
Lifecycle cost can include battery and inverter replacement cycles.
Grid, solar, and hybrid alternatives can be compared.
In regions with high tariffs, weak grid reliability, or strong solar resources, energy-system choice can change lifecycle cost dramatically.
258 regional presets make the model location-aware.
The model includes country-level, US state-level, and selected sub-national regional presets. For georeferenced models, ConduitNET can detect the model location and apply the corresponding regional cost preset automatically.
Labor and construction
Construction labor, excavation, reinstatement, and civil works vary by region and site context.
Materials
Steel, concrete, HDPE, PVC, ductile iron, GRP, tank, and pipe-material economics are region dependent.
Energy and reliability
Electricity tariffs, solar irradiance, battery economics, and grid reliability influence OPEX and energy-system choice.
Same physics. Different economics.
A georeferenced model can start with local labor, material, electricity, solar, and construction assumptions automatically. Users can then override any value when better project-specific information is available.
| Regional parameter | How it affects cost |
|---|---|
| Labor rates | Installation, excavation, construction, tank and pump-station works |
| Material prices | Pipe, concrete, steel, tank, and component costs |
| Electricity tariff | Pump OPEX and lifecycle cost |
| Solar irradiance | PV array size and solar/hybrid feasibility |
| Grid reliability | Hybrid backup and storage assumptions |
| Seismic/site context | Elevated tanks, foundations, structural quantities, and contingencies |
From component cost to unit water cost.
Cost outputs are intended to support design comparison, planning, feasibility, budgeting, and decision communication.
Capital outputs
- Total CAPEX
- Pipe, tank, pump, valve, civil, land, engineering, contingency
- Cost by component and network segment
Operating outputs
- Annual energy cost
- Energy source comparison
- Maintenance and replacement assumptions
- Raw-water or purchase costs where used
Lifecycle and unit outputs
- Present value lifecycle cost
- Annualized cost
- Cost per m³ or other unit of delivered water
- Scenario comparison across designs and regions
Unit cost calculation
The unit cost of water is computed by annualizing capital cost and combining it with annual operating cost, then dividing by annual production or delivered volume. The exact interpretation depends on the selected design period, interest/discount rate, and production assumptions.
Start with intelligent defaults. Refine toward final estimates.
The cost model follows the same philosophy as MAGNET modeling: start immediately from the best available default, then refine only where better data changes the decision.
Early planning
Use auto-detected regional defaults, standard materials, typical efficiencies, default site conditions, and standard contingencies to generate an immediate planning estimate.
Preliminary design
Update pipe material, energy tariff, soil class, cover depth, surface reinstatement, water source, tank type, pump efficiency, land class, and multipliers.
Project-specific estimate
Override defaults with contractor bids, supplier quotes, actual utility bills, route surveys, geotechnical data, land costs, and project-specific contingencies.
There is no reason to wait until the end.
Cost drives hydraulics, and hydraulics feed back to cost. ConduitNET keeps that relationship visible from the first concept through later-stage refinement.
Rigorous enough for planning. Transparent enough to refine.
The ConduitNET cost model is designed for planning-level and feasibility-level estimation. It helps compare alternatives, guide data collection, reveal cost drivers, and support early budgeting. It is not a replacement for final engineering estimates, detailed design, site investigation, or contractor pricing.
What it does well
- Early project screening
- Alternative comparison
- Regional cost sensitivity
- Hydraulic-cost tradeoff analysis
- Energy and lifecycle evaluation
- Transparent assumption review
What must be refined
- Local bid prices and supplier quotes
- Detailed geotechnical conditions
- Permitting and environmental costs
- Special crossings and trenchless methods
- Construction phasing and cash flow
- Final site-specific engineering assumptions
Professional judgment remains essential.
The model is a decision-support and planning tool. Users are responsible for validating results against local conditions, professional standards, procurement data, and project-specific requirements.
Back to ConduitNET
The cost methodology is part of the broader ConduitNET real-time design loop: geo-referenced network layout, EPANET hydraulics, water quality, operations, visualization, cost, refinement, reporting, and publication.