Monitoring the effects of a new man-made river channel

We needed to upgrade, expand and maintain an existing monitoring network tailor-made to monitor the effects on groundwater of a new artificial river channel.

The IJssel River

Monitoring the effects of a new man-made river channel between the IJssel River and Lake Dronter

CHALLENGE

We needed to upgrade, expand and maintain an existing monitoring network tailor-made to monitor the effects on groundwater of a new artificial river channel.

SOLUTION

We repurposed existing monitoring points, added new monitoring points, and switched out old equipment for a new Diver telemetry solution, in order to deliver accurate groundwater data in real time.

RESULTS

Groundwater level data has been up to date and accurate since 2020.


BACKGROUND ON THE IJSSELDELTA PROJECT

In 1993 and 1995 the Netherlands was facing extremely high water levels. Especially in 1995, the degree of flooding was disastrous and more than 250,000 people needed to be evacuated. This wake-up call led to a national flood protection program called Room for the River (Ruimte voor de Rivier). The IJsseldelta project is part of the Room for the River program and had a number of subprojects, one of which was the creation of an artificial river channel called the Reevediep. The construction work for the IJsseldelta project began in 2015 and was finally completed in 2023. The Reevediep river was officially opened in 2019 and was first used to channel excess flood waters from the IJssel river in December 2023 (see graph on second page).

This was a new river channel and its construction and usage would have effects on the surrounding (ground) water levels. However, different model studies showed that the effects would be minimal, especially since several compensatory measures were included in the project. In 2020, Van Essen Instruments was asked by Rijkswaterstaat (The National Water Agency of the Netherlands) to take over, expand and maintain an existing groundwater monitoring network that was tailored to monitor these effects.

Repurposed and upgraded monitoring location

GROUNDWATER MONITORING NETWORK

The current groundwater monitoring network consists of 85 monitoring points divided over 58 locations surrounded around the Reevediep River, close to the Dutch city of Kampen. Both phreatic and deeper groundwater are being monitored by the network managed by Van Essen Instruments.

Van Essen Instruments provided a turnkey solution for Rijkswaterstaat- and is responsible for delivering accurate groundwater levels in near real-time.

We were also responsible for supplying the equipment as well as maintenance of the monitoring locations.

Within this project the following equipment is being used:

  • TD-Divers
  • DXT cables
  • Diver-Link (both Singe and Triple)
The geohydrology includes a poorly permeable Holocene layer
(0.5m – 7m) above a highly permeable Pleistocene aquifer (approximately 120m thick), with the IJssel river intersecting the aquifer.

PROJECT IMPACT

The following aspects have had a positive impact on the overall groundwater monitoring project:

  • Repurposing materials from old monitoring points (see image on first page).
  • Using a standardized monitoring network so that it is recognized within the surroundings.
  • Addressed potential issues with landowners and any other stakeholders.
  • Continuously providing reliable data since 2020, of which 96% is complete and of high quality.

COOPERATION BETWEEN RIJKSWATERSTAAT AND VAN ESSEN INSTRUMENTS

Since 2017, Rijkswaterstaat has a multiyear contract with Van Essen Instruments, initially for a period of 5 years, which has been extended multiple times (with a potential max. of 10 years) as Rijkswaterstaat is pleased with our services. Here are some of the other Rijkswaterstaat projects we are involved in:

  • Groundwater monitoring network Ketelmeer. This network is also making use of Divers with telemetry. Although the reasons for this monitoring network are different, the scope is very similar to the Reevediep project.
  • Surface water monitoring in the floodplains of the Rivers Rhine and Maas. Making use of a custom designed Rijkswaterstaat Diver surface water monitoring setup together with a specialized TD-Diver Plus (see image below).  These Divers measure at a high rate of 1x per second (averaged over 10min and stored in the Diver), mostly measuring barometric pressure. Only during flooding events are water levels in the floodplains measured.

Both companies hope to continue and expand on this successful partnership in the years to come.

Custom-designed Rijkswaterstaat Diver surface water monitoring setup together with the specialized TD-Diver Plus

Surface water level stations during the December 2023 at apeak event.

Download the case study as a pdf