Threats Info

Source Water Protection Tables of Threats and Circumstances

Welcome to the Source Water Protection Threats Tool and Table of Drinking Water Threats (TDWTs).

This site allows users to search through the tables of drinking water threats by the various activities that could constitute a significant, moderate or low threat to municipal drinking water sources. Click here for a glossary of terms.


Change version here (Default is 2017/18):

Use the 2013 Tables of Threats version, to review all source protection plans approved prior to 2017.

Use the updated 2017 Tables of Threats version when preparing updates to source protection plans.



This website ("Site") was created by the Ontario Ministry of Environment and Climate Change ("MOECP") and the Upper Thames River Conservation Authority. Use of this Site and any of the data provided along with any text, maps and other information on the Site ("Content") is governed by the Terms of Use set out below.

Terms of Use:

The site and its content are made available by MOECP as a public service. Use of this site and any of its content is at the user's sole risk.

MOECP makes no representation or warranty of any kind regarding the site or the Content, expressed or implied, including but not limited to any representation or warranty that: (i) the content is current, accurate, complete, suitable for a particular purpose or reliable; (ii) the site or the content will be secure or available without interruption, error or omission; (iii) errors or omissions on the site or in any of the content will be corrected; (iv) any of the content will be transmitted to users; or (v) the site, related servers or the content are free of viruses or other harmful elements. The content is subject to change without notice. In no event shall MOECC or UTRCA be liable to users or others in any way for any loss, damage or injury, regardless of cause, arising from access to, use of or reliance on this site or any of the content.

Accessibility for Ontarians with Disabilities Act (AODA) Conformity

The MOECP is committed to providing a website that is accessible to the widest possible audience, regardless of technology or ability. We are actively working to increase the accessibility and usability of our website and in doing so adhere to WCAG 2.0 standards and AODA guidelines.


Email us at