Nyadi-Phidi Hydropower Project is a 21.4 MW run-of-river scheme in Marsyangdi Gaupalika, Wards 6 and 7 of Lamjung District, Gandaki Province, harnessing combined flows from the Nyadi and Phidi rivers with a design discharge of 3.6 m³/s, a gross head of 695.66 m and an annual generation of 129.14 GWh. The main intake is located near Jaluchhe village on the Nyadi River at 2,948 masl; the secondary intake is on Phidi River at 3,014 masl.

North Summit Hydro Limited has engaged IES Nepal to carry out the complete Detailed Engineering Design (DED) of all civil works, preparation of "Good for Construction" (GFC) drawings, and technical monitoring throughout the construction period which is the most technically demanding and consequential phase of the project lifecycle, translating the feasibility study into legally and technically binding construction documents that will govern every civil structure built on the project.

This is an ongoing assignment running from March 2024 to August 2027, spanning the design completion and full construction period. It represents IES's most comprehensive engineering engagement on the Nyadi-Phidi project, building on three prior assignments for the same client- hydrological monitoring, access road design and construction supervision and encompasses value engineering, design review, detailed civil works design including a Bailey Bridge across the Nyadi River, and independent review of construction power and ropeway arrangements.

What We Did

Review of previous studies and associated documents

Comprehensive review of all existing project documentation — feasibility study reports, hydrological studies, topographic and geotechnical investigation reports, environmental and social assessments, and design basis memoranda produced in prior study phases- to establish the baseline from which the detailed engineering design proceeds, identifying gaps, inconsistencies and areas requiring supplementary investigation or value engineering.

Site visit- topographic & geological findings, alternative layout study & supplementary survey needs

Conducted detailed engineering site visits across the full project layout including intakes, headrace alignment, powerhouse location, tailrace, surge shaft and all civil structure sites to verify topographic and geological conditions against the feasibility study findings, assess alternative layout options and determine the need for any additional topographical, geophysical or geotechnical investigation required before finalising the detailed design.

Value engineering- feasibility study optimisation for economic detailed design

Carried out structured value engineering on the feasibility study design to identify opportunities to reduce civil works cost, optimise structure dimensions, simplify construction methodology or improve long-term operational performance — without compromising safety, structural integrity or regulatory compliance. Value engineering findings are incorporated into the Review/Inception Report and provide the design direction for all subsequent detailed design work.

Review / Inception Report- design basis memorandum, codes & standards, test templates

Prepared and submitted the Review/Inception Report consolidating the findings of the previous studies review, site visit observations and value engineering conclusions. Submitted the Design Basis Memorandum (DBM) for client and regulatory approval, enumerating all codes and standards applicable to the detailed design and construction of each civil structure. Prepared standard templates for all in-situ and laboratory tests required during design verification and construction quality control.

Detailed engineering design- all civil works including Bailey Bridge across Nyadi River

Carrying out the complete Detailed Engineering Design (DED) of all civil structures for the 21.4 MW project: main intake weir and settling basin on Nyadi River; secondary intake and desanding basin on Phidi River; headrace tunnel or canal; forebay tank and surge shaft; penstock alignment and anchor blocks; powerhouse civil structures; tailrace channel; and all ancillary structures. Includes the structural design of a Bailey Bridge across the Nyadi River for permanent construction and operational access.

"Good for Construction" drawings- complete civil works drawing package

Preparing the full set of "Good for Construction" (GFC) drawings for all civil works — the definitive, client and authority-approved construction documents that contractors are legally and contractually required to build to. GFC drawings include general arrangement plans, section drawings, reinforcement details, formwork drawings and all dimensions, levels and tolerances required for accurate construction of every structure on site.

Review of construction power arrangements

Reviewing the proposed construction power supply arrangements — temporary power lines, generator sets, distribution networks and site load schedule — to confirm that the power infrastructure is appropriately sized, safely designed and compliant with electrical safety standards for a high-altitude construction site with multiple simultaneous work fronts including tunnel excavation, concrete works and electro-mechanical installation.

Review of ropeway alignment, bunker & camp facilities

Reviewing the proposed ropeway alignment for material and equipment transportation to high-altitude construction sites where road access is impractical, together with the design and layout of materials bunkers, storage facilities and contractor camp infrastructure confirming the adequacy of logistics support system for the construction programme and appropriately sited to minimise environmental impact and safety risk.

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