Your search for "water flow parts" revealed the following:

Lawn film: Heathland grass in three different colours: Bushes.

Sponge Green Coarse : Busch Material Non-scale 7318

Power adapter for Woodland lighting system JP5770: Woodland electronic parts for Just Plug

Light hub for Woodland lighting system JP5701 : Woodland electronic parts for Just Plug

Fibre-based material [Field Glass] Golden colour : Woodland material Non-scale FG172

Powdery material Fine turf Green : Woodland material Non-scale T45

Constant Current Diodes (around 15mA) 3pcs : Sakatsuo Electronic Components Non-scale 2908

Winter fields, the season of migratory birds : Miniatures Nature Materials Non-scale 765-24

Wall material for masonry (cut stone) 120 x 200 mm 1 piece: Kibli Plastic material N (1:150) 37961

Code Outer diameter approx. 0.8 mm Black colour : Sakatsu Material Non-scale 4515

Handrail knobs, height 1.0mm, for 0.4mm lines, pack of 6 : Sakatsuo detailing, non-scale 5001

Square bar 0.5 x 2.5 x 350 mm: Evergreen plastic material, Non-scale 125

Textile material [Field grass] Light green: Woodland material, Non-scale FG173

Spongebob Material [Underbush] Forest Blend : Woodland Material Non-scale FC139

Shaper sheet plaster : Woodland material, Non-scale C1180

Flat, square and rectangular wood 2.4 x 2.4 x 600 mm 10 pcs : Northeastern Wood Non-scale 70215

TMD-625 Decal B : Tokyo Modeling Expression Water Transfer Decal N (1:150)

LED module with magnetic switch : Purple : BitTradeOne Electronic Components Non-scale ADMGLPR

Micropac Flowerbed - Hundred Flowers : Miniatures Materials - Non-scale 731-29m

12V to 5V Conversion Adapter: Sakatau Electronic Components 2565