esshup has described above the optimal solution. If you want more information, research a "sediment pond" or a "settling pond".

I would design it such that I could easily get an excavator (or mini-excavator as pond size requires) to the location at an effective angle to periodically clear out the accumulated sediment and pivot to dump it in a place that is acceptable or easily spread.

IF you are going to build a small pond on your property, you could also consider making it a "dual use" pond. Make it a forage pond, brooder pond, etc. If you are going to spend money/time building improvements that help your large pond, might as well get a bigger bang for your buck.

There is also a more subtle physics concept at play. The amount of elevation change from the top of a stream to its local "base level" has a huge effect on the erosive power of water moving through that stream. In the steep landforms of the American West, you can easily observe the ravines that are sharply cutting into the rock cliffs. Any loose material is immediately transported down with the running water because it is well above the local base level. However, as soon as the flowing water hits the floor of the valley it immediately drops 99% of its sediment load. That is because the local base level of the valley 10 miles downstream may only be a foot lower in elevation than the base of the cliff. These deposits at the toe of the cliff are called alluvial fans.

Sorry for the long lesson, but it was necessary to explain another solution to you. Any time you can create a higher local "base level" in your stream, you will reduce the erosive power of the stream. If you have some easy spots in the seasonal stream, you could install some chuck dams. These could be almost anything based on your available materials and how you want to effect the visual appeal of the stream (if that matters). You could fell a big tree and drop the trunk across the stream, you could use rocks from your property, or free concrete demolition debris, etc. You just need to make a dam that creates a temporary pool during a heavy rain event. Your dam is probably better to be imperfect. If a bit of water runs through your rock pile dam, but it still creates a pool, then you will have reduced the erosive capacity of your stream (and the amount of sediment transported to your settling pond), yet your chuck dam will be less likely to be over-topped - which might cause erosion of the banks of your stream.

Finally, can you improve the groundcover density on your land before that surface runoff accumulates into your creek? For example, dense forest sometimes has sporadic ground vegetation. If you are cutting trees for firewood, etc., then make some deliberate clearings to enhance the growth of rooted ground vegetation for erosion control. Narrow clearings perpendicular to the slope running down the the stream would be your most efficient means of trapping sediment before it even reaches your stream.

Good luck on your improvement projects for your large pond!