I'd like to collect rain water and have it run through a filter and then into a pond.

The problem is, I can't simply run a pipe underground.

```
\\
|\\ <-- house roof
| \\
|
|                                            pond
| <--house                                     |
|                                              v
|                    [_]                                                [_]
|                    | |~~~~| |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| |
| <-- 12 ft -->      | |    | | <-- overfill drain                      | | <-- wall
|                    | |    | |                                         | |
|                    | |    | |                                         | |
|=====================\ \   | |               <o||-||-<<               / /===== <-ground
           ____________\_\__/ /                                       / /
           __________________/                                       / /
                         \ \.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o.o/ / <-bottom of pond
                          \__________________________________________/

```

Normally I would just go from the downspout, into a filter, under ground, then dump directly into the pond, but as you can see two features complicate this:

* There is the 2-ft (60 cm) high wall. I'd rather not cut a hole in the pond, that risks leaks. The pond has a 2-ft high wall around it to prevent floods from dumping sediment into it.
* There is also an overfill drain in the pond. That is so if the pond fills too much, it drains into the street. That helps direct the flood water away from the house. If the pond didn't have this, the water would spill over all edges of the pond, and damage the walls around the pond and perhaps flood the house.
* The 12 ft (4 m) space between the house and the pond is a busy path, so it isn't a good place to run a pipe, unless it is buried, but then how does the water get into the higher pond?

How can I redirect rain water too the pond when the pond has a wall?