The Netherlands province of Zuid-Holland commissioned the creation of more than 60 hectares of (water) nature in the Leenheerengorzenpolder and the Buitengorzen. With the development of this area the province has increased the area of rare freshwater tidal nature and created a beautiful walking route. We asked project manager Ronald Broekhuizen of RPS about his experiences with this project during its festive opening in Goudswaard on 6 October 2017:
Impression of the new area.
The Spuimonding is the area where the river Spui flows into the Haringvliet. The province of Zuid-Holland had already developed an intertidal nature area in 2014 on the west side of the Spui, and later it developed the eastern bank. In the beginning of 2017 the province of Zuid-Holland started to develop a wetland nature area at the Spui. Creeks, gullies and water pools have been dug in the Leenheerengorzenpolder and in the Buitengorzen. There is also a bird viewing point, car park and a walking path. It is not only a pleasant area for recreation, but it is also attractive for real delta birds and wildlife such as the spoonbill, avocet, blacktailed godwit, beaver and root vole.
Quay in the Buitengorzen.
Together with RPS, and in close consultation with the Directorate-General for Public Works and Water Management, Municipality of Korendijk, Hollandse Delta Waterboard, Natuurmonumenten and local residents, the link between the Spui and the Haringvliet has been developed in just six months’ time. The decision by the province to carry out this project through an integrated contract on the basis of UAV-GC i (Uniform Administrative Terms for Integrated Contract Forms) is courageous.
“Working with such a contract is certainly a progressive approach for a pure nature development project such as this one. With these types of projects a traditional method of contracting with RAW ii (Rationalization and Automation of Soil, Water and Road Construction) contract documents is often chosen. It was therefore important to identify the project risks with the client from the very start. If necessary, we also carried out additional preliminary studies to control the risks. After a successful tender procedure, contractor Van de Herik could start the work under the supervision of RPS.”
The excavation of an environmentally friendly bank in the Leenheerengorzenpolder.
What were the most important success factors in the process?
“It sounds obvious, but the most important success factor of this project is open and sincere communication during all phases. Not only with the client, but also with the surrounding area, contractor and other stakeholders. Moreover, we could manage the risks well by drawing up and continually updating the risk file. Furthermore, smart tendering by applying building stones has proved its added value. For example, we could make maximum use of the budget that was available for this project.”
Was there a sustainable approach in this project?
“Dealing efficiently with the soil flows was the most important task within this project, which mainly consists of earth moving. In the tender we focused on the possible recycling of the released soil, such as dike clay. This was not so easy in the implementation. The quality of the clay and its extractability proved to be less good than the preliminary studies suggested. In close cooperation with the contractor we changed the project after this in such a way that a closed soil balance could be realised. All released soil was therefore used in the project itself.”
“Hereby it was the intention to use the released soil as optimally as possible for nature objectives. A good example of this is the construction of a ‘parapet’ in the form of a low quay. This means that you can walk through the area, sheltered, without disturbing the breeding birds.”
A mattress of weips as a preparation for the bank protection at the estuary of the creek at the Spui.
What makes this project so appealing to you?
“For me this was a new and fairly progressive form of contracting and tendering a nature development project. In addition, it felt like a privilege to be allowed to work in such a dynamic, vast and beautiful environment as the Hoeksche Waard. It was great to have a positive ‘nature result’ immediately after realising the work.”
Could you give an example of this?
“In the beginning of May the contractor completed the connection of the creek with the Spui, so that the area was influenced by tides. Four days later we received a cheerful email from a local nature expert in which he spoke about a ‘dream start’. Many ‘real’ delta species, which we had hoped would come here had already found the area within a few days.”
“For the experts: the ringed plover, little ringed plover, golden plover, grey plover, dunlin, red knot, curlew sandpiper, little stint, temminck's stint, common greenshank, wood sandpiper, redshank, green sandpiper ... I am probably forgetting one or two!”
Bank protection at the estuary of the creek at the Spui.
What were the learning points?
“With this project, also with nature development, we learned that it helps to give a contractor as much freedom as possible for drawing up the design, requesting the permits and smartly devising the project. With the experience gained in this project we will give the market even more freedom in a subsequent project by coming up with smart and high-quality solutions.
By limiting the content-related engineering work as much as possible, we can also focus more on selecting the most suitable contractor for a project through a sophisticated tender procedure.”
What tips do you have for other clients if they would like to start up such a project?
“Keep a good focus on selecting the right contractor with experience and a passion for nature development. And at the same time focus less on the content of the work. Dare to detach yourself from the content at the front and give the future contractor the opportunity to apply his knowledge and experience. Even for this type of nature construction work.”
Project manager Ronald Broekhuizen at the Leenheerengorzenpolder before the start of the project:
i Uniform Administrative Terms for Integrated Contract Forms. ‘UAV stands for Uniform Administrative Conditions for the execution of works and technical installation works 2012 (UAV 2012). The UAV can be declared applicable in a contract or construction contract in construction. The UAV regulates the contract relations between the client and the contractor.
With the application of the UAV, a specification or contract of agreement is simplified because many administrative matters can be omitted in the specification text. Specifications and agreements are more uniform when applying the UAV. In this way, the drafting of an agreement or specifications becomes less labour-intensive.
The UAV 2012 is the result of cooperation between the construction sector and the government. The UAV has become a standard scheme that is applied to projects of the government and projects in the private sector. NB: this is not a 'Standard Regulation' as it is meant in a legal sense.’ Wikipedia.
ii The RAW (Rationalization and Automation of Soil, Water and Road Construction) system refers to a standardised delivery approach of legal, administrative and technical conditions used in the Netherlands for the contract construction for land, roads and water. It is a well-established system that has been applied to the majority of Dutch infrastructure projects over the last thirty years.