Hanoi is planning to spend US$5 million to spruce up Sword Lake and its surrounding area for the celebration of the capital's 1,000th anniversary in October.
The projects are expected to be completed by the end of June before the anniversary.
One project to improve and beautify the lake's embankment, flower gardens, plant decorations and paths will cost an estimated VND40 billion ($2.1 million).
Another worth more than VND46 billion ($2.4 million) will include replacing or adding public lights around the lake as well as at attractions in the area such as the Turtle Tower, the Ngoc Son Temple and the The Huc Bridge, Hanoi People's Committee vice chairman Nguyen Van Khoi said at a city meeting.
Khoi said all plant and flower work around the lake should be done this month.
He asked investors and contractors of the projects to be careful as the lake was a "sensitive" spot, for the city and the country.
Contractors have to finish one task before starting another, in both projects, and make sure wastewater from their work does not flow into the lake, Khoi said.