The Colorado River has been significantly affected by damming and diversion, with the most accurate statement regarding its condition being:
The Colorado river routinely does not reach the sea because it dries up miles before it would do so.
Damming and diversion for agricultural irrigation, urban use, and hydropower have drastically altered the river's natural flow, especially in the lower reaches. These alterations have contributed to the river often being unable to reach its delta at the Sea of Cortez, leading to ecological and environmental concerns.
The other statements are not accurate:
- The Colorado River is not a healthy ecosystem, especially due to the introduction of non-native species and the ecological changes caused by its management.
- Riparian areas along the Colorado River have seen significant changes, including habitat loss and degradation due to these management practices.
- The river does not typically cause significant flooding, largely because of controlled water management through dams, which mitigates flooding risks.
Overall, the balance of ecological health has been disrupted by the extensive human interventions along the Colorado River.