Were Cartagena's moats stagnant water?

Would Cartagena's defensive moats have become dangerous pools of stagnant water?

Not necessarily; a moat could be dry or use moving water, and engineers tried to prevent the standing water that worsened disease risk.

Defensive moats could be dry or supplied with running water. Engineers in this climate understood the dangers of standing water and tried to keep it moving. Their plans did not always work, but moat design included efforts to manage sanitation and disease risk.