Using ArcGIS 10.8 I successfully ran through the following geoprocessing tools to complete a flow accumulation analysis of a USGS 1/3 arc second DEM of a portion of Houston, TX:
Fill --> Flow direction --> Flow accumulation
However, the results appear way more granular than I anticipated... Black lines are flow accumulations and red lines are neighborhood boundaries (see below screenshot).
I have no background in hydrology but given the geography/terrain of Houston I had anticipated seeing "ponds" or pools of accumulation rather than lines that follow only certain streets and the very centerlines of streams. How should these accumulation flows be interpreted considering the widespread flooding that happened after Hurricane Harvey and other major storms? What might be a target resolution that would allow me to derive larger "pools" of accumulation in this urban context?