The East Demerara Water Conservancy, often called the EDWC, is one of Guyana's major water storage and flood control facilities. It is located in Region No. 4 - Demerara-Mahaica. Over 500,000 citizens of Guyana inhabit the basin that lies below and between the sea defences and the EDWC Dam in a 48 km band from Georgetown to Mahaica.
Contents
- Location
- History of the EDWC
- EDWC Quick Facts
- Japan International Cooperation Agency JICA Component I Supply of Excavators and Pontoons to the NDIA for the use in the EDWC
- JICA Component II Rehabilitation of the EDWC
- The EDWC Northern Relief Channel
- References
The EDWC serves to irrigate thousands of hectares of rice and other crops within this area by storing rain water for dry periods and it also provides one of the primary source(about 60%) of drinking water for the city of Georgetown.
To complement the irrigation network, a number of drainage relief structures have been built to protect the EDWC Dam from over-topping and collapse during the rainy periods.The most recent of there structure is the EDWC-Northern Relief Channel, better known as the Hope Canal. The Hope Canal is a man made canal that connects the EDWC to the Atlantic Ocean. Its primary function is to prevent over-topping of the conservancy dam by releasing the excess water directly into the Atlantic to prevent flooding and its consequences. The Hope Canal program consisted of four components - the Head Regulator, the Public Road Bridge, the High Level Sluice and the Hope Canal (10.3 Km)
Location
The EDWC is located 15 miles south of the most densely populated section of the Guyana Coast. It is bounded to the North by a man made 45 mile earthen dam and to the deep south by a natural topographic rise composing largely of ancient coastal dune formation over geological time. The EDWC Dam is constructed of clay and pagasse(an organic soil also known as tropical peat and of similar composition to the commonly known peat).
History of the EDWC
Guyana's drainage and irrigation system has its origins in the late 1600s under the Dutch colonial rule.
One of the major innovations of the time was the building of water conservancies (artificial water catchment empoldered reaby earthen dams) to retain fresh water from upland streams during the dry seasons and release via irrigation canals and head regulators.
The EDWC is one of the most important of these conservancies and it was designed over 125 years ago by William Russell and built using Slave Labour. Over the past several decades, changes in the land use, climate change driven increases in rainfall intensity and a number of other factors have left the EDWC in a fragile state.
The National Drainage and Irrigation Authority has worked and continues to work diligently with international assistance to maintain and protect this vital National Drainage and Irrigation Network.
EDWC Quick Facts
Japan International Cooperation Agency (JICA) Component I – Supply of Excavators and Pontoons to the NDIA for the use in the EDWC
As a part of the JICA Project which sees the Japanese Grant Aid being utilized to improve the drainage and irrigation capacity within the EDWC, Eight (8)long reach excavators and two pontoons were donated to the Government of Guyana.
The excavators and pontoons were assembled locally and operators were given essential training in their use. They were deployed immediately after the handing over ceremony in November 2012.
JICA Component II – Rehabilitation of the EDWC
The second component of the programme was the rehabilitation of six (6) key structures within the EDWC.
- Sara Johanna Sluice
- Nancy Intake
- Annaadale Intake
- Ann's Grove
- Shanks Intake
- Maduni Sluice
The handing over ceremony of these newly rehabilitated structures from JICA to the Government of Guyana was on the 5th July, 2016.
The EDWC-Northern Relief Channel
The EDWC NRC (Hope Canal) project was designed in response to the 2005 floods that East Coast, Region 4 experienced due to the over-topping of the conservancy dam. The Hope Canal seeks to provide the means to release excess water in the EDWC when it is in danger of over-tapping and breaches.
The project is a 10.3 km long earthen channel with a three-door head regulator at the conservancy end of the canal and an eight-door outfall sluice at the Atlantic end.
Also included in the project was the construction on a public road bridge that has been in operation since February 2014.