Algae returns in Lincoln Memorial reflecting pool, complicating plan to recolor it to “American flag blue,” report says

Algae has resurfaced in the Lincoln Memorial reflecting pool, according to a report from The Guardian on June 16, complicating President Donald Trump’s administration plan to change the pool’s water color to resemble “American flag blue.” The report said the water has turned green again during warm weather, undermining an earlier administration claim that the algae would be cleared as part of the ongoing work.

The reflecting pool’s condition has become an unexpected public-facing issue for the administration’s high-profile effort tied to the Lincoln Memorial. The Guardian reported that Trump described the site during earlier remarks as “filthy” and “dirty,” and framed the project as a bid to restore the location as a “beautiful” monument. The reported budget figure for the effort was $14.2 million.

In the same report, The Guardian said the administration had claimed algae in the pool would be removed after the renovation. Instead, it described algae continuing to proliferate, with the pool returning to a green appearance. The report attributed the renewed spread to warm weather, suggesting that conditions favorable to algae growth are outpacing the controls used during the renovation process.

Officials’ specific technical steps for algae management were not detailed in the Guardian account, and no independent public record was cited in the reporting excerpt provided. As a result, details such as whether the renovation schedule has been adjusted, whether chemical treatments have been modified, or whether the color-control effort has been paused remain unclear.

For the administration, the practical stakes are immediate. A reflecting pool that cannot maintain a stable appearance affects public perception of a federal memorial site and can also increase operational costs tied to repeated cleaning, monitoring, or reworking of water treatment systems. It also raises questions about whether the project timeline, and any related contractor schedules, will need to be extended.

The reported episode also highlights a broader challenge in managing outdoor water features on historic public property, where temperature, sunlight, and nutrient levels can accelerate algae growth. Even when restoration plans are underway, controls that work under one set of conditions may not hold under another, particularly during seasonal heat.

What happens next depends on how federal facilities managers respond to the renewed growth. If the administration’s recoloring goals are still active, further treatment and testing may be needed before the pool can meet whatever visual standard is being sought. If the color-control effort has been deprioritized, the immediate emphasis may shift to stabilizing water quality and preventing recurring algae blooms.