Background In the past, the Westzaan Natura 2000 site was an area of brackish water due to a regular inflow of salt water. However, since the closure of the Zuider Zee in 1932 by the Afsluitdijk between Friesland and Noord-Holland, the water has become fresh, threatening the ecological value of the site. Westzaan is one of the few areas where a former brackish peat meadow habitat, now threatened by the fresh water conditions, can be regenerated. Furthermore, in fresh water the vegetation develops in such a way that open spaces become scarce, which could become a threat to root voles (Microtus oeconomus). With the change from brackish to fresh water, the degradation of peat takes place on a large scale. The resulting particles lead to water turbidity, reducing the growth of water plants. This is a threat for fish such as the bitterling (Rhodeus sericeus subsp. amarus) and the spined loach (Cobitis taenia). Polder Westzaan is a pSCI that includes Annex I Habitats Directive types such as the Atlantic salt meadows; Northern Atlantic wet heath lands, hydrophilous tall herb fringe communities of plains, transition mires and quaking bogs. Objectives The aim of the project was to restore the brackish ecosystems in the Westzaan polder by reintroducing salt water, while at the same time safeguarding other activities, such as agriculture and leisure. Furthermore the project intended to prepare the way for large-scale dredging and nature development works, to fully utilise the brackish conditions. The Habitats directive Annex I habitat types are: Atlantic salt meadows, Northern Atlantic wet heath lands, hydrophilous tall herb fringe communities of plains, transition mires and quaking bogs. The directly targeted Habitats directive Annex II species are: Microtus oeconomus subsp. arenicola, Myotis dasycneme, Cobitis taenia and Rhodeus sericeus subsp. amarus. The project aimed to create a saltwater inlet in the North Sea Canal in the south of the area, from where a sufficient quantity of salty water could be siphoned across the dyke, from nine metres deep. The intention was that the water would be pumped into the surface water of the project area through an underground pipe, ultimately reaching the whole of the most northerly point of the Westzaan polder (the Guisveld). Fresh and salt water were to be kept separate in areas where farmers were still grazing cattle; provisions were also to be made for the passage of recreational vessels. The project objectives included management, monitoring and communication activities. Results The project was concluded prematurely in 2008 and did not achieve its objectives. Social developments in the area, particularly the lack of support from farmers, led the beneficiary to conclude that the project could not be conducted as originally envisaged. Due to this lack of support from the stakeholders, Staatsbosbeheer considered the legal and financial risks too high to fulfill the position of project leader, and consequently to continue in its role as beneficiary. The activities of this shortened project, during its 23 months, involved preparatory actions and communications: setting up the project organisation, collecting information and developing plans, subcontracting studies and reports, and communication with stakeholders. No field restoration measures were implemented.