Course of Mylnes Culvert incorrect at this point. I have an Environment Agency map showing the correct course: 
• St Stephens Street
• Under St Stephen's Garden
• Along Marsh Street to Prince Street.
A stormwater culvert runs from my pin and under the Centre to Cascade Steps. This is the culvert that many Bristolians believe is the River Frome, as it was before the construction of Mylnes Culvert.
If you need to see the map you can email me: jackmartinleith@gmail.com.
Thanks for giving this your attention.
Jack