Unfounded rumors linking an extreme weather event to human attempts at weather modification are again spreading on social media. It is not plausible that available weather modification techniques caused or influenced the July 4 flash flooding along the Guadalupe River in Texas.

Plans to develop a flood monitoring system in the Texas county hit hardest by deadly floods were scheduled to begin only a few weeks later.

The State Flood Plan, published last year, identified $54 billion in flood mitigation, warning and data needs. The state has awarded around $660 million since the plan was published, with a special legislative session coming soon.

Texas officials and Hill Country leaders knew the risks of flooding along the Guadalupe. Warnings went unheeded, flood warnings, river gauges and sirens unfunded — and more than 130 Texans died.

With more than 170 still missing, communities must reconcile how to pick up the pieces around a waterway that remains both a wellspring and a looming menace.

Here's what to know about the deadly flooding, the colossal weather system that drove it and ongoing efforts to identify victims.