Flooding – streams and rivers


Many of us have seen the brown trout by Spitalford Bridge. But what about the stream life that is harder to see?  Volunteers from HKD Transition and the Hassocks Amenity Association have been surveying aquatic life in the Herring stream where it enters the village in Parklands Copse, and where it leaves at Friars Oak.  After quarterly stream surveys we have a much better sense of stream life than when we started in January 2016.

Shrimp are the only species we found in every sample at both sites, but Bullhead fish are almost always present.  We commonly find larvae of different species of mayfly, caddis fly, blackfly and midges, sometimes cranefly and demoiselle larvae.  There are worms, segmented or flat, and snails or bivalve molluscs.  Often Riffle beetle or Diving beetle larvae appear (and sometimes the beetles themselves), and we have found leeches several times.

All of these creatures are fascinating to watch.  There was the time that a mayfly larva hatched out in the warmth from the microscope (we put it outside but it probably didn’t survive the cold).  Some Caddis fly larva make a ‘case’ from sticks and stones to protect themselves from predators: one of our favourites had incorporated a tiny piece of gold tinsel into its home.  There have been rarities like the larva of Atrichops crassipes, the Least Water-snipefly.

We have found differences between our two sites: contrary to expectations, Friars Oak consistently has more species (and more of the species that are especially sensitive to pollution) than Parklands Copse.  It may be because there is more water in the stream by Friars Oak, as five more tributaries join the Herring through the village.  It may be that there are issues relating to the upstream farmland.  We’re now changing our sampling sites so we can get a better sense of the whole stream.

We volunteers are learning as we go along, with a lot of training and support from the Ouse and Adur Rivers Trust.  We start wading in the stream, measuring water depth and speed, then use our dipping net to gather a sample from the stream bed.  The bullhead fish are counted and put back in the stream immediately, and the rest of the sample is returned to the same site after identification.

Indoors a digital microscope linked to a laptop allows us to identify the tiny invertebrates hiding in the sample.  It looks like mud and sticks when we spread it in trays, but study closely and things start to move. The shrimp are easy: they dart about in a characteristic sideways movement.  Others are harder to spot.  Only with a long look does a piece of twig suddenly appear to have legs, identifying it as one of the Cased Caddis fly larvae. A tiny black dot reveals itself under the lens to be a water mite. A puzzle over which species of mayfly larva we’re looking at requires working through keys in several reference books.

For non-biologists the quarterly glimpse of what lives alongside us in the Herring stream is captivating.  If you’d like to join the team you’re most welcome. Just email herring@hkdtransition.org.uk to find out more.



Hassocks Amenity Association and HKD Transition held a joint meeting on flooding in Hassocks to consider what actions are being taken and what more can be done.

The meeting was a huge success with speaker Dusty Gedge providing numerous examples of where changes can be made.

Dusty was joined by Juliet Merrifield of HKD Transition, Peter King of Ouse and Adur Rivers Trust, Fred Maillardet from HAA and Kevin Macknay from West Sussex County Council, pictured above, to update people on local flood management.

Visit Dusty’s suggested sites at




Sussex Wildlife Trust has come up with a number of suggestions which we can do as individuals to counteract flooding locally.

The Trust says: We want to help people to influence their environment and to help tackle our water and wetland issues. There is a whole wealth of ways that you can help improve the health of our rivers and wetlands in Sussex. For ideas, see our Make a Difference pages, or help us with some of the following :-


Reducing Flood Risk in Hassocks  – A Report by Peter King of Ouse and Adur Rivers Trust. February 2016