The group’s infrastructure civils operation was also impacted by two significant contractual disputes, which it hopes to resolve this year.
Latest private company accounts published at Companies House also restated the previous 2017 year, from a breakeven position to a £2.7m loss.
After a far-reaching review, Clancy said it had now altered criteria on which it accepts new work to avoid excessive risk or tying up too much working capital.
A round of senior management changes were also completed three months ago with the appoint of Matt Cannon as new chief executive officer.
Revenue remained static at £263m.
Joint chairman Kevin Clancy said the outlook for 2018/19 was far more positive.
He said: “We expect Clancy Docwra to return to profit and to generate positive cash flow.
“Our performance in the first half of the year is in line with internal expectations.
“We started the year in a strong position with 97.6% of our projected turnover already secured from a total order book of £1.2bn.
“We are experiencing a surge in demand in the water sector and anticipate that it will be sustained into the medium term driven by increased industry investment necessitated by challenging leakage reduction targets.
“Since the year end, we are pleased to have renewed our funding arrangements, including securing long-term banking facilities.”