It is very clear that the flood meadow isn't flat! The accurate topographic survey clearly shows the low channels in blue where the main flow across the meadow occurs once the river overtops. It is also noted that the banks around the upstream end of the meadow are raised which prevents the floodplain becoming functional until later on in a high rainfall event. This very valuable topographical survey will be used to make decisions on the best way to manage the meadow for an uplift in biodiversity and provide a reduction in flood risk.
by Mike Hopkins
Detailed Topographic Survey
Storm Geomatics is a surveying company that focusses on capturing geospatial data in and around water. The data is mostly used to inform flood mapping projects and environmental studies however it has been used for a multitude of other interesting and watery projects too! Storm Geomatics threw all available resources on the regeneration project and coordinated a magnificent team effort to get the five hectare flood meadow surveyed in 2 hours flat! The survey results will provide a detailed floodplain map showing flow paths and spill points as well as the legacy embankments made up of dredging's from the 1980s. By understanding how the floodplain functions will help inform the best management plan for biodiversity across the meadow. Storm Geomatics will continue to support Storm Wildlife and will be measuring the river channel, bridges and flood tunnels in the area to add to the flood meadow data and create a hydraulic model of the immediate river catchment. The model is then used to experiment with potential changes to the embankments and management of the meadow to produce the optimum outcome for an increase in biodiversity and flood alleviation.
by Mike Hopkins
Part of the baseline survey requires a habitat assessment which is scored by sampling small areas of the field and identifying different vegetation species within the sample. By creating a species rich grassland will provide a more diverse habitat for a wider range of living things to thrive and multiply. A senior ecologist from Middlemarch Environmental carefully analysed the sample plots and found an average of 6 species per sample with common species being rye and timothy grasses, dandelion and dock. It will be a few weeks before the full report is available and the ecologists have enough survey information to calculate the baseline biodiversity value of the site. Once this is available we will be in a better position to decide how we can create an uplift in the biodiversity of the meadow. A species rich grassland would have more than 15 plant species per square meter with more than 30% cover of wildflower and sedges. Could this be our target for the meadow and what is the best way to achieve this? Hopefully all will be revealed soon!
by Mike Hopkins
The surveys begin!
Today we are looking at the soil structure and nutrient levels in different areas of the meadow. This could inform us that we need to manage different parts of the meadow in different ways to achieve better biodiversity and flood alleviation. We are finding that soil depths vary in relation to the overland flow paths - interesting! These surveys and many more will all be used to create a management plan that will maximise biodiversity and have the greatest benefit to flood alleviation.