If you are the only person likely to be affected in the future, you may have make this a personal issue. But if there are others in your position, who may be affected in the future, you may be able to get some help in establishing a pre-emptive by-law.
I would be proposing something for the next AGM, suggesting the committee establishes some criteria for the size, shape, colours and materials that future pergola could be made from.
Meanwhile, raise a complaint with the committee about the noise from and appearance of the pergola on the grounds that you mention – interfering with the peaceful enjoyment of your lot (noise from rain) – as well as the requirement for owners to maintain the appearance of lot property.