Turtruba, Region 7
The initial estimate of the potential installed capacity for this site was 320 MW, but the study carried out by the developers, Enman Services Ltd., has estimated an average power output of 760 MW with optimization of the dams. An MOU was signed with the developers in 2001.
This project would require the construction of an access road and transmission lines. It is envisaged that power would be available within 6-8 years of construction.

The potential power to be produced is intended for export from Guyana to Brazil and in the future as a Phase 2 project to Trinidad & Tobago.

Summary Data of the Initial Feasibility Study

•Total storage
18.5 MAF (million acre-feet)
•Live storage
11.8 MAF
•Full supply level (FSL)
195 ft
•Low supply level (LSL)
140 ft
•Normal tail water level (TWL)

195 ft
13,000 ft
•Total volume
30,112,00 cu yd

•Volume concrete (including transitions)
593,000 cu yd
245 ft
275 ft
•Radical gates
4 -50 ft X 65 ft high
•Discharge capacity
11,325 m³/s

Power Station
•Rock elevation
300,000 cu yd
•Volume concrete
635,000 cu yd
936 ft

Turbines 10 X 110 MW (Francis)
Generators 10 X 122,000 KVA at 0.9 pf and 100rpm
Transmission 2,345 KV circuits to Linden
Average net head developed for Energy 163 ft
Minimum net head developed for Power 130 ft
Reservoir drawdown 65 ft
Plant capacity at maximum head 1100 MW
Plant capacity at average head 918 MW
Plant capacity at minimum head 650 MW
Firm energy (dependable) 487 MW
Average energy 760 MW

Devil’s Hole, Region 7
An MOU was signed in February 2007 with Guyana Goldfields Inc. for a period of two years to conduct a feasibility study. This site has a proposed continuous energy of 62 MW but, is initially intended to supply 35 MW of electricity to its mining site at Aurora.

Arisaru, Region 7
Government of Guyana and the Guyana Poverty Alleviation Group signed a Memorandum of Understanding in August 2003 to study the Arisaru site. This MOU was for a period of two years which has since expired. This site has a potential of 120 MW.

Upper Mazaruni, Region 7
RUSAL, a Russian Company was granted exclusive rights in February 2007 for an initial period of three years to conduct a pre-feasibility study of this site. This site has a potential installed capacity of 1320MW and the Company is proposing to set up an Aluminum Smelter as the primary load centre.

Based on previous studies, the following key parameters of the Upper Mazaruni Hydropower Station were identified in the RUSAL report

Summary Data

•Catchment area 10,890 km²
•Normal annual runoff 20.2 km³
•Normal annual discharge 640 m³/s
•Maximum discharge 2,400 m³/s
•NMOL 498.5 m
•Dead-storage level 483.0 m
•Evacuation depth 15.5 m
•Total storage capacity 15.0 km³
•Active storage capacity 13.8 km³

•Site Sand Landing
•Foundation sand-rock and apogrit
•Height 55.0 m
•Crest length 240.m
•Quantity of fill 625,000 m³
•Location on the right bank of reservoir
•Foundation sand-rock and apogrit
•Discharge capacity 5,000 m³/s
•Number of bays 4
•HPS intake chamber
•Location on the left bank of Mazaruni River
•Number of bays 2

•Foundation sand-rock and apogrit
•Design discharge 600 m³/s
•Diversion tunnel
•Geological surrounding sand-rock and glomeration
•Length 11.4 km
•Diameter 10.0 m
•Station sluices
•Geological surrounding sand-rock
•Length 2.3 km

•Diameter 3.0 m
•HPS Powerhouse
•Type underground
•Geological surrounding diabase
•Design discharge 600 m³/s
•Number of units depends on option (12 X 183.3 MW; 4 X 550 MW; 6 X 367 MW)
•Turbine type radial-axial (Francis turbines)
•Maximum head 430 m
•Tailrace conduits
•Type trough-shaped two-line with re-inforced concrete lining 0.25 m thick
•Geological surrounding diabase and sand-rock
•Length 1.6 km
•Diameter 10.0 m

Page 2 of 3 1 2 3