Not sure if this is something the community here has interest in.

A section of the creek bank has fallen away, revealing that all of the soil has been recently deposited (~ last few decades). The garbage inclusion likely spreads for dozens or maybe hundreds of cubic meters of earth. We don’t want to disturb the soil to clean this out so we’re limited to surface level cleaning.

On the flipside: it’s lots of deep fertile topsoil. The fast growing weeds, like lantana, absolutely love it.

  • WaterWaiverOP
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    1 year ago

    The waterways & stormwater outlets are more complex in terms of ownership than it just all being national parks, the local councils (third tier of Australian government, below federal & state) and Sydney water are also involved. I believe the creek water is managed by one authority and the creek bed a different authority, just to make things more fun.

    While it’s urban sediment, it’s probably relatively clean.

    What do you mean by clean? Mostly insoluble and chemical stable solids, little in the way of soluble pollutants and insoluble liquid pollutants?

    but ultimately, they rock armoured it using 60 cm+ sized boulders to stop the erosion

    Upstream of this at the outlet there was big rockwork installed years ago, much of which is bigger than 60cm, but a lot of it has still washed around and collapsed. I’ll see if I can grab some pictures next time I’m there.

    Reclamation is tough, and it’s heart-breaking sometimes,

    We only focus on some very small patches of a very large regional park. More than half of it (by my estimates) is taken over by vine weeds (mostly balloon vine, morning glory & madeira) that smother the native trees – if you blur your vision then it looks like verdant green rolling hills. Small native plants only survive in some sections, others are completely overtaken by tradescantia (wandering jew) and lantana.

    Occasionally some commercial bushcare contractors come through to work sections, but again only small (and more accessible) areas. The national park is also a rail corridor and no-one is allowed near that without lots of prep + supervision (+ money to pay for supervision), so those bits are generally bad.

    Now I get to figure out how to fix shitty disturbed sites. Sits a little better with me.

    Glad you’ve found some power over the chaos. Hope it’s not too heart wrenching.

    • Track_Shovel@slrpnk.netM
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      1 year ago

      Yay. A bureaucratic nightmare!

      What do you mean by clean?

      As in likely below environmental guidelines for contaminants of concern (metals, hydrocarbons, organic compounds). And by relatively they are probably circum-threshold values. If I were to go to sample it I would expect a lot of variability.

      I can’t imagine the invasive plants issues you guys have down there.