Delta Works needed level of flood protection and the resulting costs are a recurring subject of debate, and involve a complicated decision-making process. In 1995 it was agreed in the Delta Plan Large Rivers and Room for the River projects that about 500 kilometres of insufficient dyke revetments were reinforced and replaced along the Oosterschelde and Westerschelde between 1995 and 2015. After 2015, under the High Water Protection Program, additional upgrades are made. In September 2008, the Delta Commission presided by politician Cees Veerman advised in a report that the Netherlands would need a massive new building program to strengthen the country's
Delta Works future demands. The latest upgrades are made under the High Water Protection Program. During the execution of the works, changes were made in response to public pressure. In the Nieuwe Waterweg, the heightening and the associated widening of the dikes proved very difficult because of public opposition to the planned destruction of important historic buildings to achieve this. The plan was changed to the construction of a storm surge barrier (the Maeslantkering) and dikes were only partly built up. The Delta Plan originally intended to create a large freshwater lake, the "" (Zeeland Lake). This would have caused major environmental