Here in the South East we’ve had the driest June since records began (in 1910), with only 3.3 mm of rainfall recorded for the month. This being the case, it’s not surprising that flood management isn’t something on the mind of most people. But, Natural Flood Management techniques, such as tree planting, woody debris dams and ditch blocking can also be of benefit during droughts.
Recent rainfall levels compared with the long-term average (Southern Water, 2018) https://www.southernwater.co.uk/regional-rainfall
There are lots of human activities that increase the likelihood of rivers and streams drying up or experiencing low flows. One of the most significant is our conventional approaches to land and water management. Historically, land management has considered water somewhat of a nuisance, and every effort was made to encourage water off of the land and out to sea as quickly as possible. After removing trees and hedgerows, digging ditches, installing land drains under fields, constructing river embankments, and dredging, channelising and clearing debris from our rivers, water now travels quickly downstream.
In most cases, Natural Flood Management is focused on reversing these activities and restoring the ability of the land to slow and store water. In doing so, water is once again allowed to infiltrate into soils and slowly drain into surface waters, or percolate deeper into soils and replenish groundwater stores, resulting in a more steady supply of water to rivers and streams. By reintroducing woody debris to streams, not only does it help to ‘slow the flow’ but it also encourages a more diverse flow pattern (which is often lacking due to channelisation and lack of debris) and influences geomorphological processes, including the formation of scour pools. These pools can be an important refuge for aquatic organisms during droughts, and if the stream does completely dry up, woody debris is likely to benefit burrowing invertebrates by providing heavily shaded areas where sediment remains moist for a longer period of time.