One of the tasks our volunteers are undertaking is a detailed survey of the Calder Catchment tributaries.  We started this in early 2016 and recently finished surveying the Hebden Water catchment which includes Hebden Water, Crimsworth Dene and the river through Nutclough woods.

The picture below is of a section at Crimsworth Dene which is typical of the scenery and the beautiful landscape we live in.

We have seen some terrific scenery in the last 12 months and now have a much better understanding of this part of the catchment and how the rivers may react to rainfall.   Our river surveys are assisting in the efforts to identify the most appropriate places to focus on when we are choosing places for Natural Flood Management solutions, such as the ‘Log Jams‘ planned for Hardcastle Crags and Crimsworth Dean.


All photos are geo-located, so you can take a tour of the catchment from the comport of your armchair


In Google Earth you can click on the names to view individual photos (This photo Crimsworth Dean)

Get the Google Earth photo map now!


Click to Download kml file

The link above will download the file “Calder Catchment River Network Survey.kml” to your local downloads folder. You can then open the file in Google Earth, where it will appear as an additional item under ‘Temporary Places’.

(NB. You will need Google Earth installed, and an internet connection. Google Earth Pro is available as an App, or to download for free here: https://www.google.com/intl/en/earth/download/gep/agree.html using your e-mail address (as your username) and license code GEPFREE.


Slow The Flow volunteers are measuring the Calder tributaries from up on the moorland, to down in the valley. This informs locations for NFM interventions

The photographs from the tributaries survey work are all geo-referenced, and uploaded to our Google Earth map, so that we can easily see where we have been, and refer to the photographs.

The reference numbers relate to a detailed spreadsheet (available on request) containing information on river width and depth, plus other notes.

The detailed spreadsheet information for river modelling is available on request
Spreadsheet available on request

Information in the spreadsheet is accurate, the photo locations on the Google Earth map are more approximate, based on internal GPS of photographic devices, rather than the accurate survey information contained in the spreadsheet.  If you require the detailed and accurate information for flood modelling, do get in touch and we can make it available.

If you are just interested to see what we have been doing, the Google Earth map offers an interesting overview of the catchment, and a sense of the scale of our volunteer’s efforts.

We have done a lot, but there is plenty still to go. The map is updated each time we have been out collecting more data, check back to watch it develop!


The Google Earth file is arranged in layers, so you see an overview, or zoom in to find a tributary

The Google Earth file is arranged in layers, so you see an overview, or zoom in to find a tributary