These beavers might have then swam into the Santa Margarita River. Beavers are ecosystem engineers. They utilize many woody species in dam building as well as for feeding. Beaver dams impede the water flow and large pools often form behind them. Beaver dams greatly affect water flow dynamics.
Beaver dams lead to decreased current velocity by physically impeding the rate of water flow.
This can, in the future, affect the kinds of plants which will grow in abandoned beaver ponds. The precipitation stored during the rainy season is gradually released throughout dry periods. This gradual release of water may be of concern in the Santa Margarita River where the native ecosystem is adapted to occasional dry spells during the summer. This may result in flooding which can destroy wetland vegetation that had previously lived in the area. In the spring and fall, beaver cut down trees and shrubs for feeding and dam-building.