01
Project Setting
Geographical setting, geology, topography, soils, climate and the physical suitability of the Hare River command area for irrigation development.
Original engineering study preserved · Modern reassessment planned
The HARE
Project
Irrigation Engineering · Hydrology · Hydraulic Structures
A detailed 1995 irrigation-engineering study of the Hare River area near Arba Minch, preserving the original design logic for irrigation demand, hydrology, canals, regulators, diversion headworks and associated hydraulic infrastructure — and creating the foundation for a modern technical reassessment.
HARE Irrigation System
Conceptual engineering pathway
1995
River
Headworks
Main canal
Fields
Diversion weir
Under-sluice
Regulators
Canal drops
Conceptual web diagram only — not a reproduction of the original engineering drawing.
Project overview
From River Hydrology to Irrigated Fields
The HARE Irrigation Project Design Report was completed in 1995 by Mesfin Hagos, Mitiku Bedru, Seid Shimelis and Tamir Mitiku as a Bachelor of Science in Engineering design project at Arba Minch Water Technology Institute. The preserved report describes an integrated study of the Hare River irrigation system: physical setting, water quality, irrigation demand, hydrology, canal-system design, regulators, drops and diversion headworks.
Original study
1995
BSc Engineering design report
Study location
~10 km NW of Arba Minch
As described in the 1995 report
Water source
Hare River
River system draining toward Lake Abaya
Engineering concept
Diversion irrigation
Headworks + canals + control structures
Archival consistency note.
Professional records of the original team cite the thesis/design project as “Design of HARE Irrigation Project (1500 ha)”, while the abstract of the preserved 1995 report describes the detailed scheme as irrigating a command area of about 1,000 ha. The HARE Digital Archive preserves both source statements. The difference will be reconciled only through the continuing document-by-document technical review rather than silently altering the historical record.
Physical setting
A Site Considered Favorable for Surface Irrigation
The 1995 report describes the irrigation area as gently sloping terrain associated with an alluvial plain. The land rises and falls locally and includes small erosion gullies, but the overall topography was judged favorable for surface irrigation.
Hare River is described as originating in the Chencha Mountains at elevations above 3,000 m above mean sea level and flowing through gorges toward Lake Abaya. The report gives an average stream gradient of about 3.5 percent.
Topography
Gently sloping alluvial plain, locally undulating, considered favorable for surface irrigation.
Soils
Medium-textured alluvial materials including sandy loam, loam and sandy clay; estimated infiltration rate of approximately 10–30 mm/h.
Soil reaction
The report characterizes most soils as neutral to alkaline, around pH 7–7.5, with no significant salinity problem identified.
Rainfall record
For the climate data used in the report, annual precipitation is described as varying from approximately 625 to 1,054 mm, with two principal rainy seasons.
Original technical scope
The Engineering System Designed in 1995
The report progresses from the physical and agricultural basis of irrigation to the hydraulic structures needed to control and deliver water. The sections below summarize the main design domains preserved in the original study.
02
Irrigation Water Quality
Assessment of sediment, dissolved salts, sodium, potentially toxic elements, bicarbonate, bacterial contamination, salinity and groundwater-management considerations.
03
Crop & Irrigation Demand
Crop-water requirements, effective rainfall, net and gross irrigation requirements, crop scheduling and diversion requirements using FAO-based procedures.
04
Hydrological Analysis
Analysis of Hare River flow records, annual peak flows, flood-frequency estimation and 1-in-5-year dry-period flows for design and water-availability assessment.
05
Canal System Design
Primary and secondary canals, field layout, tertiary drainage, canal capacity, permissible-velocity design and regime-theory comparison.
06
Regulators & Drops
Canal falls, distributary head regulators, cross regulators and related control structures for flow regulation, measurement, silt control and canal operation.
07
Diversion Headworks
Weir type and site selection, canal head regulator, under-sluice, divide wall, marginal bund and ancillary hydraulic works required to divert the Hare River.
08
Engineering Comparison
Comparison of calculated design results with information from the existing Hare irrigation works, including discharge, weir dimensions, canal layout and drop structures.
Hydrological foundation
Designing for Floods, Dry Flows and Irrigation Demand
Hydrology was central to the study because the diversion and canal system had to be considered against both flood risk and water availability. The report analysed Hare River flow records, momentary annual peak flows and dry-period flows, and estimated irrigation demand using crop-water requirements and effective rainfall.
Peak-flow analysis
Annual momentary peak-flow records were used in the flood-frequency work supporting hydraulic-structure design.
1-in-5 dry period
Monthly dry-period flows were analysed as part of the assessment of dependable water availability for irrigation.
FAO-based demand
Crop evapotranspiration, effective rainfall and net/gross irrigation requirements formed the basis of crop and diversion-demand calculations.
Water control
Canals, Regulators and Diversion Headworks
The original report compares two canal-design approaches: unlined sections based on regime theory and lined sections based on permissible-velocity criteria. The design process considers how silting and erosion affect canal capacity and full-supply depth.
Head regulators and cross regulators were treated as operating elements of the system rather than isolated structures. The report describes their roles in controlling off-taking discharges, measuring flow, reducing silt entry, maintaining upstream water levels during low flow, isolating canal reaches for repair and helping manage fluctuations in the network.
At the diversion, the design scope includes the weir, canal head regulator, under-sluice, divide wall, marginal bund and associated works. The purpose of the headworks is to regulate river level and divert the required flow into the canal system, including during periods when natural river levels are low.
Design chain
- Hare River flow and flood assessment
- Weir and diversion-control concept
- Canal head regulator and under-sluice
- Main and secondary canal conveyance
- Cross regulators and distributary regulators
- Drop structures and turnouts
- Field delivery and drainage
HARE Revisited
Past Calculations, Present Understanding
The original report will remain preserved as a historical engineering document. The modern reassessment is a separate layer: it will reproduce, test and reinterpret the earlier work using today's geospatial data, hydrological methods and modelling tools while keeping the 1995 calculations visible for comparison.
Original study · 1995
Engineering with the Data and Methods Available Then
- Field reconnaissance and available topographic information
- Historical climate and river-flow records
- FAO crop-water estimation procedures
- Manual / tabulated hydrological-frequency analysis
- Regime-theory and permissible-velocity canal design
- Conventional hydraulic and structural calculations
- Comparison with information from the existing Hare irrigation project
Modern reassessment · planned
Re-analysis with Modern Hydrology, GIS and Digital Terrain
- DEM-based catchment and terrain delineation
- GIS mapping of slope, drainage, land cover and command area
- Modern rainfall and hydroclimatic datasets
- Updated flood-frequency and low-flow analysis
- Digital crop-water and irrigation-demand workflows
- Hydraulic modelling and reproducible calculations
- Direct comparison of original and modern design decisions
DEM & Terrain
Re-delineate terrain, slope, drainage pathways and command-area geometry using modern digital elevation models and GIS.
Catchment Hydrology
Revisit rainfall, streamflow, flood-frequency and dry-flow analyses using modern datasets, reproducible statistical methods and updated hydrological tools.
Land & Irrigation
Reassess soils, land cover, irrigable-area suitability, crop-water demand and irrigation layouts using contemporary geospatial data.
Hydraulic Review
Re-examine diversion, canal and hydraulic-structure concepts with modern modelling, design standards and transparent calculation workflows.
Why preserve HARE?
An Engineering Project That Continued Beyond Graduation
HARE is valuable not only because of what was calculated in 1995, but because the project became an early engineering foundation for four professionals whose later careers developed across complementary parts of the water sector.
Central HARE principle.
“Bringing the project back into print therefore connects engineering education with professional experience, and past calculations with present understanding.”
Original engineering team
Four Engineers, One Shared Technical Beginning
The Digital Archive gives each engineer an individual professional record while preserving the HARE project as a collective work.
MH
Eng. Mesfin Hagos Tewolde
Irrigation Engineer · Hydrologist · Civil Engineer
MB
Dr. Eng. Mitiku Bedru Gochefo
Hydraulic Engineer · Irrigation Specialist · Water Resources Leader
SS
Eng. Seid Shimelis
Irrigation & Water Resources Engineer · Dams · Headworks
TM
Eng. Tamir Mitiku Habeteyes
Hydraulic & Hydropower Engineer · Irrigation · WSS · Wastewater
Project history
1995 to the Digital Archive
1995
Original Design Report
The four-member engineering team completed the HARE Irrigation Project Design Report as a Bachelor of Science in Engineering project at AWTI.
1995–2026
Professional Experience
The four engineers developed careers across irrigation, hydrology, dams, hydraulic engineering, WASH, wastewater, project leadership, government advisory work and digital water systems.
2026
Digital Archive
The original project is being preserved online together with the engineers’ professional histories, the project book and the technical source material.
Next
HARE Revisited
A modern technical reassessment will compare the original 1995 engineering decisions with current DEM, GIS, hydrology, hydraulic modelling and water-resources practice.
Continue through the HARE Digital Archive
Explore the project book, the original engineering team and the developing maps, terrain and modern reassessment sections.