The Limehouse Cut was built under the River Lea Act of 1766, and provided access to the Thames from Hertford. RCD was opened in 1820, and initially had no connection to Limehouse Cut. However, I see that the Regent's Canal took ownership of the Limehouse Cut from January 1st 1854, and created a link from the basin, but was filled in in May 1864. Not until 1968 was there another direct navigable link.
Non of the maps I have seen dating back to 1855 through to 1968 show any link, though most are devoid of specific details anyway.
More detailed information on water variances in Wikipedia HERE. Quite interesting that.
More from Richard Thomas's website HERE. Even more interesting.
- and HERE.