There is evidence that the river was used for navigation in the thirteenth and seventeenth centuries, but in 1790, an Act of Parliament was obtained to enable the river to be improved from Ipswich to Stowmarket. This was achieved by building 15 locks, and the river was then known as the Ipswich and Stowmarket Navigation, although the name has now fallen out of use. The navigation was opened in 1793, and although few records were kept of income and expenditure, the enterprise appears to have been profitable. In 1819, there was talk of expansion, but nothing came of the plans. In the 1840s, as railways arrived in the area, the Trustees negotiated with the Eastern Union Railway, and the navigation was leased to them for 42 years. At the end of the lease, it was in a poor state, despite the fact that the railway had a legal duty to maintain it.