Invasive non-native species (INNS) are a problem for flooding

In this guest blog post, Anna Orr of the Environment Agency explains how you can help when out and about, by simply reporting the locations of INNS on the INNS Mapper app/website.

Invasive non-native species (INNS) Mapper

INNS Mapper is an app and website for reporting sightings, surveys and management of invasive non-native species (INNS).  INNS Mapper is free to use and aims to provide an effective resource to support INNS programmes and coordinate treatment efforts. Data reported to INNS Mapper is open access and publicly available for anyone to use. 

What are INNS?

Invasive non-native species (INNS) are species that have been accidentally or intentionally introduced by people or animals into a location where they don’t naturally occur. The negative impacts are far reaching for the environment, economy and society. It is important to prevent the spread of INNS, understand the locations where INNS are found and appropriately manage populations in our environment. 

INNS and Flood Risk
Himalayan balsam and Japanese knotweed are two invasive species that are found in Calderdale. In summer they outcompete native plants but die back in winter leaving riverbanks and valley sides exposed and bare. This means rain water flows faster over these surfaces increasing the likelihood of soil erosion, landslides and the risk of flooding. This is obviously a real problem in Calderdale where the landscape is so steep and we need to try to slow the flow of water into our rivers.

How can INNS Mapper help?

You can use INNS Mapper to report sightings of INNS while you are out and about in Calderdale using the “Report an invasive” function on the app. Here you can submit locations of INNS on a map and include details such as what the species is, how many plants there are/how big an area they cover, and also add photos. If you’re unsure as to whether you have correctly detected an invasive species, you can use the identification guide on the app which includes a description and photographs of each plant. Alternatively you can use these online identification sheets . All of the sightings that are reported on INNS Mapper can then be viewed by a range of partners in the Calder Valley who are working together to tackle invasives. The locations identified will help to inform where treatment might need to take place to strategically tackle the problem of invasives in Calderdale.

Download the INNS Mapper app today from your phone’s app store and visit the INNS Mapper website at

See our previous blog post we regularly use our volunteer sessions to help tackle Himalayan balsam at Hardcastle Crags NT (you can find out when those sessions are at