The 1790s were a period of prosperity for the navigation, as trade increased. In 1796 George Knowsley, a banker who was one of the mortgagees, proposed further improvements, but although William Chapman produced plans, they were considered too expensive. Two years later, the commissioners were working with William Wilberforce, their local Member of Parliament, to ensure that the proposals for the Beverley and Barmston Drainage Bill would not adversely affect them. In 1797, they considered again the problems posed by the small opening beneath Hull Bridge, and although Beverley Corporation initially said that they would never alter it, an agreement was reached after protracted negotiations, and in July 1801, an Act of Parliament was obtained to authorise its replacement. The new bridge was operational by April 1804, half the cost having been met by Richard Bethell, owner of the Leven Canal, on condition that the tolls for passing beneath the bridge were significantly reduced.