Fleet Brook is a small river in northern Hampshire, England and tributary of the River Hart. Route The source is somewhere near the town of Fleet, and the river that flows out from Fleet Pond is marked as Fleet Brook by the Ordnance Survey. The permanent streams that flow into Fleet Pond are known as the Gelvert and Brookly Streams. They are all treated as part of Fleet Brook by the Environment Agency, for the purposes of monitoring water quality. Reservoirs near Parkhurst Hill are №s 1-5 to exclude non-existent 4, south-east of Fleet. Their water treatment is north of №2. The Environment Agency measure water quality from downstream of the intake. The Gelvert stream wends north, passing under Bourley Road, and is joined by another, which rises from a spring to the west. The stream gets its name from Gelvert Bottom, marshy terrain as it passes under Aldershot Road. Another stream and surface water drains join before it is crossed by the A323 Norris Hill Road and passes under the Basingstoke Canal where it receives overflow water from a pair of weirs. Others join before it dissipates into reed beds on the south-eastern edge of Fleet Pond. The Brookly stream begins on Greendane Copse, a little to the north-west of the reservoirs. It is culverted under a sports ground, and then reappears until it reaches Aldershot Road, beyond which it crosses housing estates in Church Crookham and Fleet, largely in culvert, but with short open sections. In Oakley Park, it is exposed again, and has an inflowing stream, an overflow on the Basingstoke Canal, and passes under the A323 road and Albany Road to reach the south end of the park. Three more bridges carry the B3010 Kings Road, Southby Drive, and Avondale Road over the watercourse. At this point it is joined by a further stream described below. It then flows into the south-west corner of Fleet Pond. A third stream begins in the Forest of Eversley near a five-sided enclosure, the ex-Church Crookham Military sewage works, licensed to discharge at most 1.56 Ml per day in the early 1990s. The stream passes by Fleet Infants School, designed by Michael Hopkins and Partners replacing the Victorian school, under the canal and through housing estates, remaining on the surface until it reaches Brookly Gardens, beneath which it is now culverted to join the second stream. An old OS shows