It was during one of these walks that Rowland noticed a molehill that had been dug into a local stream such that water from the stream exited the bottom of the molehill. He noticed that the grass under the stream was considerably more lush than the grass around it. He set about attempting to duplicate the system on the Golden Valley properties. The work took twenty years, from about 1584 to 1604. The main component was a three-mile (5 km) long artificial channel leading from the Dore at Peterchurch, running alongside it, and finally back into the Dore at Abbey Dore. The result was a large plot of land between the Dore and the trench that could be flooded. The "Trench Royal", as he called it, was wide and deep for the first half-mile, and then wide and deep for the rest. A sluicegate at the downstream exit controlled the flow of water into the fields; closing it would flood the fields, opening it allowed the water to drain off again. The use of flooding increased the yearly value of the land from £40 to £300 per year.