Lee Flood Relief Channel

Lee Valley Regional Park is a 10,000-acre (40 km2) 26 miles (42 km) long linear park, much of it green spaces, running through the northeast of Greater London, Essex and Hertfordshire from the River Thames to Ware, through areas such as Stratford, Clapton, Tottenham, Enfield, Walthamstow, Waltham Abbey, Cheshunt, Broxbourne and Hoddesdon in an area generally known as the Lea Valley. Greater London's largest park, Lee Valley Park is more than four times the size of Richmond Park, extending beyond Greater London's borders into the neighbouring counties of Hertfordshire and Essex. The park follows the course of the River Lea (Lee) along the Lea Valley from Ware in Hertfordshire through Essex and the north east of Greater London, through the Queen Elizabeth Olympic Park to East India Dock Basin on the River Thames. The park is managed by Lee Valley Regional Park Authority and is made up of a diverse mix of countryside areas, urban green spaces, heritage sites, country parks, nature reserves and lakes and riverside trails, as well as leading sports centres covering an area of over 10,000 acres (40 km2). It is crossed by a number of roads and railways. There are several major reservoirs and multiple water courses (rivers and canals) within Lee Valley Park, both to carry the river flow, and also to provide navigable waterways and flood relief channels.

The River Lee Country Park is located in the Lee Valley Park and is managed by the Lee Valley Regional Park Authority. Covering 1,000 acres (400 ha) on either side of the River Lee Navigation between Waltham Abbey and Broxbourne, it is an area of lakes, watercourses, open spaces and three Sites of Special Scientific Interest (SSSI) linked by footpaths and cycle tracks. The site straddles the Hertfordshire/Essex boundary.

Waltham Abbey SSSI is a 34.2-hectare (85-acre) biological Site of Special Scientific Interest which is located within the Waltham Abbey Royal Gunpowder Mills at Waltham Abbey in Essex.

Waltham Common Lock (No 10) is a lock on the River Lee Navigation at Waltham Cross in Hertfordshire, England. The lock is located in the River Lee Country Park and stands close to the Broxbourne White Water Canoe Centre. At the tail of the lock is the Powdermill Cut dug in 1806 to connect the Waltham Abbey Royal Gunpowder Mills directly to the then-new navigation.

The Royal Gunpowder Mills are a former industrial site in Waltham Abbey, England. It was one of three Royal Gunpowder Mills in the United Kingdom (the others being at Ballincollig and Faversham). Waltham Abbey is the only site to have survived virtually intact. The Royal Gunpowder Mills, Waltham Abbey, were in operation for over 300 years. Starting in the mid-1850s the site became involved in the development of revolutionary nitro-based explosives and propellants known as "smokeless powder". The site grew in size, and black powder became less important. Shortly after the Second World War it became solely a Defence Research Establishment – firstly the Explosives Research and Development Establishment, then the Propellants, Explosives and Rocket Motor Establishment Waltham Abbey; and finally the Royal Armament Research and Development Establishment Waltham Abbey. The Mills are an Anchor Point of the European Route of Industrial Heritage, set in 175 acres (0.71 km2) of parkland and containing 21 buildings of major historical importance.

The Lea Valley, the valley of the River Lea, has been used as a transport corridor, a source of sand and gravel, an industrial area, a water supply for London, and a recreational area. The London 2012 Summer Olympics were based in Stratford, in the Lower Lea Valley. It is important for London's water supply, as the source of the water transported by the New River aqueduct, but also as the location for the Lee Valley Reservoir Chain, stretching from Enfield through Tottenham and Walthamstow.

Fishers Green is a settlement in the parish of Waltham Abbey in Essex, England, lying 1 mile (1.6 km) to the north of the main built-up area. It lies on the flood plain of the River Lea.

The Cornmill Stream and Old River Lea is a 24.6-hectare (61-acre) biological Site of Special Scientific Interest in Waltham Abbey, Essex.

The Millhead Stream is a minor tributary of the River Lea in England. The stream flows north to south across the Waltham Abbey flood plain and through the site of the former Royal Gunpowder Mills.

Canoeing at the 2012 Summer Olympics in London were contested in two main disciplines: canoe slalom, from 29 July to 2 August, and canoe sprint, from 6 to 11 August. The slalom competition was held at the Lee Valley White Water Centre and the sprint events were staged at Eton College Rowing Centre, at Dorney Lake, known as Eton Dorney. Around 330 athletes took part in 16 events. The men's 500m sprints were replaced by a 200m race; in addition, the men's C-2 500m was replaced by a women's K-1 200m sprint. This was confirmed at an International Canoe Federation board meeting at Windsor, Berkshire, on 5 December 2009. For the first time, women competed in two individual events in sprint canoeing. Because of the changes, the finals were spread over a three-day period instead of the traditional two days which had been in effect since the 1976 Games. The most successful nation in the slalom was France, with two gold medals in the four events, followed by Great Britain with one gold and one silver. In the sprint, Hungary was the most successful with three gold, two silver and one bronze medal, while Germany topped the medal table overall, with three gold, two silver and three bronze medals.

Lee Valley White Water Centre (previously known as Broxbourne White Water Canoe Centre) is a white-water slalom centre, that was constructed to host the canoe slalom events of the London 2012 Olympic Games. On 9 December 2010, Anne, Princess Royal officially opened the venue which is owned and managed by Lee Valley Regional Park Authority. The £31 million ($50 million US) project to construct the centre finished on schedule and was the first newly constructed Olympic venue to be completed. The Olympic canoe slalom competition was held from 29 July through 2 August. The venue also hosted the 2015 ICF Canoe Slalom World Championships.

Waltham Town Lock (No 11) is a lock on the River Lee Navigation at Waltham Cross, Hertfordshire. The lock is located in the River Lee Country Park which is part of the Lee Valley Park. The adjoining Showground site now known as the Broxbourne White Water Canoe Centre has been chosen to host the canoeing event in the 2012 Summer Olympics.Flowing close to the lock is the River Lee Flood Relief Channel known as the Horsemill Stream at this point.