<Tr> <Td> - coordinates </Td> <Td> 50 ° 55 ′ 30" N 1 ° 28 ′ 45" W ﻿ / ﻿ 50.9251 ° N 1.4792 ° W ﻿ / 50.9251; - 1.4792 Coordinates: 50 ° 55 ′ 30" N 1 ° 28 ′ 45" W ﻿ / ﻿ 50.9251 ° N 1.4792 ° W ﻿ / 50.9251; - 1.4792 </Td> </Tr> <Tr> <Td_colspan="2"> River Test highlighted in red, shown in South East England </Td> </Tr> <P> The River Test is a river in Hampshire, England . It has a total length of 40 miles (64 km) and it flows through downland from its source near Ashe to its estuary at Southampton, where it converges with the River Itchen to form Southampton Water . In its upper reaches it is a chalk stream, and is used for fly fishing for trout . </P> <P> The river is managed by the Environment Agency, whilst the Port of Southampton is the navigation authority for the tidal section below Redbridge . </P>

Where does the river test start and finish
find me the text answering this question