Linked to the retail price index, £50m will mature in 2048 and the remaining £50m in 2054. They have deferred purchase dates of June 2020 and June 2021.
Tideway is stumping up £3.1bn of the super sewer project's total £4.2bn cost, with the remainder coming from Thames Water.
Last month Tideway agreed a £700m loan from the European Investment Bank (EIB).
Tideway chief financial officer Mark Corben said: "This innovative, deferred-purchased bond issue marks Tideway's debut on the capital markets. Combined with our loan recently agreed with the EIB, it will help secure the financing for our long-term investment programme, locked-in at 2015 rates. It is another key step forward in our work to clean up the River Thames."
Main construction work on the Thames Tideway Tunnel is due to start later this year and be completed by early 2024.
Construction of the £4.2bn project (2011 prices) will be under three main contracts:
- BMB JV (BAM Nuttall, Morgan Sindall and Balfour Beatty) has the £416m West contract
- FLO JV (Ferrovial Agroman UK and Laing O'Rourke Construction) has the £746m Central contract
- CVB JV (Costain Vinci Construction Grands Projects and Bachy Soletanche) has the £605m East contract.
Stretching 25km through the heart of London, the main tunnel's inner diameter will measure 7.2 metres. It will have a storage volume of 1.24 million cubic metres and run up to 66 metres underground, largely following the course of the river.
Tideway is the trading name of Bazalgette Tunnel Limited, established in August 2015. Its shareholders are a consortium of investors comprising funds managed by Allianz Infrastructure Luxembourg, Amber Infrastructure Group, Dalmore Capital Limited, and DIF from the Netherlands.