Its possible to think of the Living Planet as One Being, One Essence of Life.  Along with that, we can imagine there is an Immune system to keep it all in finest health. 

What are the pieces of the Earth's Immune system?  Consult creekbed ecology.  There are factors that reliably accompany the Outstanding Resource, lively places where diversity thrives. 

What all does Mother Nature need to supply her Members with the miracle of Life?  The following are the things Mother Nature creates for Herself, if allowed by human beings.

She keeps a band of trees upon the land that borders each side of the streambed, to shade the creek and hold the bank with their roots.  Under these trees, there is vegetation close to the ground that holds the soil and serves as filter to the rain and what it carries to the creekwater.  This area is called a Riparian Zone.  A sufficient area is 10 meters or so of forest life, on either side. 

Nature also keeps resilient plant life covering where the waterline draws an edge:  to keep Bank Stability, not eroding on either side. 

She will have her own pattern of meander.  There is a rhythm that is intrinsic to every slope: these bends are best left undisturbed.  How humans harm this is Channelization.

When curves are straightened for human convenience, this speeds the water's flow.  Too fast flow is not contained by the creek's long held pattern, and cuts a new path at downstream bends.  Excess of cobble dumped downstream in great loads can then cramp Channel Flow. 

Lady Nature has cobble, nooks and crannies, hiding places for tiny bugs and bigger fish.  This is called Epifaunal Substrate. 

Life loves the cobble to be free of siltation, not to clog up these homes - suffocate and displace the creatures within.  The degree of siltation present is called Embeddedness.

When all the Balances have been met and the creek life is thriving, it plays within a range of water movements, deep-fast to shallow-slow.  That all Velocities are present is the measure of this arena for survival of the finest.  Here, the sweet spot of evolution.  When there are many options, the animal capable of making choice best survivies. 

Next: Creekbed Biology