Upper Bulbourne Readings for April 2020 submitted by Bob Farrer

Dear All,

Here are the latest readings for the Bulbourne, together with a rainfall summary and some nature notes.

The picture of the Kingfisher comes from a friend who lives in central Berkhamsted. A short section of the Bulbourne flows through her back garden. Perching on the drain provides a good view of activity in the stream below.

image1

Kind regards,

Bob

Upper Bulbourne Aquifer. Depth Readings and Rainfall Summary.

April 2020. Date of observations: 29th April

Location Findings

Dudswell Bridge 0.90 metre below datum.
Very brisk flow of clear water through narrow channel and under-road duct. There is abundant weed.
Flow rate is 15 litres per second.

Northchurch
(Recreation Ground) No depth reading possible. Casing is broken.
Stream varies in width here from 1.5 to 4.0 metres. The narrower channels have a fast flow, revealing a clean gravel bed. Water is clear. Max depth here is approx 16 cm. Some willow branches have fallen across the stream but they are too small to dam the flow.

Northchurch

(Primary School) 0.55 metre below datum.
Stream varies between 2- 3.5 metres wide. There is a brisk flow over weed and gravel. Water is clear. Max depth approx 20cm.

Billet Lane

Berkhamsted 1.0 metre below datum.
Very strong flow of clear water through all three under-road channels.
Max depth approx 30cm in centre channel.

Grand Union Canal.
Engineering work. Both the Cowroast and Northchurch groundwater pumps were off at the time of these observations

Comments: The beautiful warm and sunny weather of most of April gave way to a brief cold wet spell at the end of the month. Rainfall for April, at Dudswell, was 39 mm. Two thirds of this fell in the last four days. The much needed rain, (an ironic phrase after such a wet winter) has led to an explosion of plant growth. The river at Dudswell, the highest datum point, still looks full but plant growth in the stream bed has reduced flow velocity since last month’s reading.

The swan pair is now nesting again at Northchurch but the female has part of her upper beak missing. Mr. Clark, who visits the swans every day, believes the injury was the result of an attack by dogs last weekend. We hope that she will be able to eat sufficiently as her energy needs will be higher now that she is laying.