ASTEC
 

Poza Honda / La Esperanza Irrigation Project

Area: N/A
Date Consultancy began: November 1984
Date Consultancy ended: June 1986
Total Contract Amount: USD $2,374,001.40
Name of associated firms: Association PROMON-TECNOSAN (Brazil)/ASTEC-INELIN-INGECONSULT-GEOPER-ING. H. ALMEIDA
Customer: Center for Rehabilitation of Manabí
Characteristics of the Project:

Conceptually, the water will be transferred over two independent sections, and the flow rates transferred will be regulated and distributed for each reservoir. The Poza Honda section, serving the Portoviejo River valley, comprises an intake – pumping station – drive line system to raise the flow to a head of 100 m up to the intake of the tunnel that cuts through the mountain range on the border between the Daule River basin and the coastal valleys of this province. At the other end of the tunnel, the flow is conducted to the Poza Honda reservoir, which receives it and then regulates and distributes the water supply. The whole section totals 24 km, from the shores of the Daule River to Poza Honda.
The La Esperanza section, serving the valleys of the Carrizal and Chone Rivers, starts at an intake located upriver from the Daule-Peripa dam, in its reservoir, with 8.3 km of tunnel to cross the border mountain range, and then by gravity feed to the La Esperanza reservoir.
The project was done in two different phases:

Feasibility

The scope of work was defined on the basis of general aspects, describing the activities for each phase of the study, indicating for Phase I – Feasibility the following three main activities: Preliminary Studies, Studies of Alternatives and Complementary Studies of the alternatives selected.

The preliminary studies involved analyses of field information, geological and geotechnical studies, studies of water resource, agricultural development, water demands, and the system’s water balance, to identify several alternatives for a comparative evaluation based on activities including:
  • Programming and doing topography;
  • Programming and doing geotechnical research;
  • Layout studies;
  • Hydraulic, geotechnical, structural, mechanical, and electrical pre-sizing for intake facilities on the Daule River, Daule-Peripa reservoir and "La Esperanza" reservoir, pumping station on the Daule River, forced adduction from the Daule River, dam on the Daule River, hydropower station on the Daule River, regulation tank, canals and tunnels;
  • Auxiliary works such as accesses, maintenance roads and energy supply;
  • Cost estimate;
  • Planning based on decisions about project implementation and construction stages;
  • Pre-feasibility, considering direct and indirect benefit estimates, standard costs and operating and maintenance costs, financing conditions, costs per cubic meter of water transferred and profitability
Final Designs

The final design was established for all elements comprising the project’s works, determined in the Advanced Preliminary Design, with the exception of the hydropower plant, and submitted for consideration by INECEL, with the following main activities:
  • Defining specific design criteria;
  • Complementary geological and geotechnical research;
  • Complementary topographical studies, including networks of triangulation and polygonal support and the axes, leveling, cross-sections rainfall surveys of specific areas;
  • Plan for transfer facilities, including the final report, design blueprints with project location, quarry location, layout of facilities, excavations, framing for reinforcement and detailed listings of reinforcement, floor plans, longitudinal and transversal profiles, treatments for special problems;
  • Attachments with calculations of safety coefficients and design standards, and the details of all hydraulic, structural, foundation, geotechnical, mechanical and electrical calculations.
  • Estimated budget, with the amounts of works and unit prices considered on the basis of performance of work and equipment.

ASTEC @ 2009