Thanks @themerrylotus
This site is special. Id not have thought swales were important on flat sand! But then i witnessed the impact of salt and silt in tbe upper layers that cause the water to run over and not soak into the soil.
So actually they are very important in this setting
More organic matter is certainly on the shopping list its just been difficult to access in bulk so far..
Only rice hulls and coconut husks so far