What would happen to the organisms if several house owners nearby fertilized their lawns followed by a big rain storm?

If several homeowners fertilized their lawns and then a big rainstorm occurred, the excess fertilizers could wash off the lawns and into nearby water bodies, leading to nutrient pollution. This influx of nutrients, particularly nitrogen and phosphorus, could result in algal blooms, which deplete oxygen in the water and create dead zones, harming aquatic life. Additionally, it could disrupt local ecosystems, affecting organisms both in the water and those reliant on the affected habitats. Overall, the health and balance of the local ecosystem would be significantly compromised.