The alternative site was chosen following the discovery of some contamination at the original Spitalbrook site last October which made the proposed development of the site unviable.
The new site in Hertfordshire remains within the Borough of Broxbourne and is six miles closer to the Olympic Park in East London , meaning a shorter travel time between the venue and the Olympic Village where athletes will stay in 2012.
The new venue is situated on what is currently the overflow car park for the Showground site of the River Lee Country Park, and retains the benefits of the original site.
It lies just north of the A121, between Waltham Cross and Theobalds Grove stations and has excellent transport links.
A full site investigation has been conducted, and deemed suitable for the proposed development.
Given the suitability of the site and its similarity to Spitalbrook, the original design concepts for the venue can also largely be transferred and accommodated on the new site, helping keep the project on track and maintaining the legacy benefits of the development.
This venue change for the Games has been approved by the International Canoe Federation (ICF), the International Olympic Committee, and the British Olympic Association.
After the Games, the venue will be developed to become the White Water Canoe Centre in Broxbourne, delivering a major leisure attraction for canoeing and white water rafting as well as a major competition venue for elite events.
The Centre will be managed by the Lee Valley Regional Park Authority, who own the land.
During the Games seating will be installed around the venue for spectators to sit and watch the action.
Sebastian Coe, chairman of London 2012, said: “This is very good news.
"It gives us a world class venue for Games time and an excellent facility for elite athlete and community usage after the Games, living up to our promise of leaving a lasting legacy for sport.
"We have worked closely with the Olympic Delivery Authority (ODA) throughout the feasibility works and we have developed an excellent solution.
"Still within the Broxbourne borough and Lee Valley Regional Park Authority area, the site is closer to Olympic Park, allowing athletes to reach the venue within 30 minutes during the Games.
"We look forward to seeing this exciting venue taking shape.
David Higgins, chief executive of the ODA , said “Delivering the venues and infrastructure for the 2012 Games is a huge project and it is important we take swift action when presented with challenges.
"Having robust contingency plans in place has allowed us to make practical decisions on relocating the Broxbourne venue and the official confirmation we have now received for the new site gives us excellent momentum as we prepare to start construction work at the start of next year.
"The new site gives us the platform to deliver a world-class venue for 2012 while retaining the huge legacy benefits these new facilities will deliver to Broxbourne and the East of England region for many years to come”.
Simon Toulson, general secretary of the ICF, said: “The ICF has worked closely with the London Organising Committee and the British Canoe Union on the two sites.
"The new site looks ideal with a natural setting, convenient for spectators and athletes.
"It has the potential to be an excellent leisure canoeing centre for the community post-Games.
"The ICF is looking forward to seeing this site develop into a world standard venue for canoeing in time for the Olympic Games in London .
Shaun Dawson, chief executive of Lee Valley Regional Park Authority (LVRPA), said: “We are delighted that a part of London 2012 is coming to Broxbourne.
"This is great news for the local area, the Eastern region and also for the Lee Valley Regional Park Authority, which is proud to be involved in the development of this world class sporting facility.
"This site in the River Lee Country Park will be a fantastic venue for the Olympic White Water Canoe Centre. And beyond 2012, we are committed to delivering a major sporting and leisure attraction for this area – a true and lasting Olympic legacy.”
The ODA and the LVRPA are carrying out public consultation on the plans for the White Water Canoe Centre locally on April 21 and 22 ahead of a planning application being submitted in the coming weeks.
Subject to the planning application being approved, construction is due to begin in early 2009 with the venue completed for Games training and testing in 2010 and 2011.
Stephen Castle, Essex County Council cabinet member for the 2012 Games, said: "It is really wonderful news to hear the showground in Broxbourne has been officially unveiled as the canoe course for the London 2012 Olympic and Paralympic Games.