The thinking behind this work is that by slowing the flow of the headwaters of the Seal Brook, a tributary of the Mease, nutrients and phosphate-carrying sediments will settle out in the woodland. To this end, a range of interventions have been introduced.
Leaky barriers slow the flow of water during high flow events. Leaving the stream undisturbed during low flow, the barriers can help settle out nutrients, as the water travels at a slower speed.
Swales and scrapes
Adding small storage areas across the flowpath of water slows the flow and adds valuable time for nutrients, including phosphates to settle.
The ponds were designed with inlets and outlets, where the outlet level was higher than the inlet level, which enables sediment and associated phosphate settle out into these ponds before heading off further downstream.
This scheme was funded by the River Mease Developer Contribution Scheme, which is in place to mitigate the negative impacts of nutrient levels in the River Mease SSSI that is caused by new developments within the catchment area.
The site is subject to extensive monitoring which will tell us more about the effectiveness of the scheme and help inform future projects.