Bunker Design Specification

Bunker Design Specification
Simplified Architect Draft

An integrated drainage and form-retention design for new bunker construction

Prepared for golf course architects and design-build teams considering SandSave during original construction.

1. Purpose

Conventional bunker construction often asks the liner to do two jobs: separate sand from the subgrade and drain water. Those jobs conflict. A liner that drains water is also acting as a filter. Over time, that filter traps fines and organic material, which reduces flow.

SandSave separates the jobs:

Form and separation are handled by the liner, edge system, or suitable native subgrade.
Drainage and sand cleaning are handled by the SandSave Drain Box, tied directly to the course drain main.

The result is a bunker designed to keep its shape and maintain drainage without relying on a fabric or porous liner to remain unclogged forever.

2. Design Summary

A SandSave-integrated bunker has four functional layers:

Layer	Component	Purpose
1	Bunker sand	Playing surface. Use the architect's normal bunker sand specification and depth.
2	Edge / face system	Holds the designed shape, edge line, and face geometry. Required in every bunker.
3	Floor treatment	Provides separation and erosion control only. Liner use is decided per bunker based on subgrade.
4	SandSave Drain Box + 4-inch outlet	Collects water, enables active sand washing, and ties into the course drain main. Required in every bunker.

3. Floor Treatment: Decide Per Bunker

Because SandSave provides the drainage path, the floor liner is no longer selected for drainage. It is selected only for separation, erosion control, and subgrade protection.

3.1 When a floor liner may be omitted

A floor liner may be omitted where soil testing confirms dense, stable, low-permeability subgrade such as heavy clay. In that case, the native subgrade serves as the separation layer, and SandSave handles drainage from the sand and subgrade surface up.

3.2 When a floor liner is still recommended

Use a floor liner where the subgrade is loose, sandy, mixed, unstable, or likely to contaminate the bunker sand. In these cases, choose the liner for durability and separation, not as the primary drain.

Permeable fabric or porous aggregate liner: use where lateral water movement toward the Drain Box is helpful.
Non-permeable liner: use where a hard separation from the subgrade is preferred and water should be routed directly to the Drain Box.

In all cases, grade the floor treatment toward the SandSave Drain Box rather than toward a perimeter trench drain.

3.3 Confirm by testing

Do not assume one floor design for the entire course. Confirm subgrade type, permeability, and stability at each bunker. A course may have some bunkers with liners and others without liners.

4. SandSave Unit Placement and Connections

Install one SandSave Drain Box at the engineered low point of each bunker. This is the same general collection point a conventional design would drain toward, but SandSave also allows active maintenance and sand washing at that point.

Component	Simplified Specification
Drain Box	One per bunker. Polymer sump box. Install cover flush and 4 inches below finished sand surface.
Outlet	4-inch outlet tied directly into the course drain main.
Coupler Box	One per bunker. Waterproof box outside the bunker, out of play and outside the mowing line. Provides quick-connect access.
Mobile Controller	One per course. Battery powered, tool-free quick-connect, 100 psi system. Used to service all SandSave bunkers.

Place the Coupler Box with the same care used for sprinkler heads, yardage markers, and other visible course infrastructure. It should fit the routing, play pattern, and mowing pattern.

5. Edge and Face Retention

The edge/face system is separate from drainage. It is required because bunker edges tend to move over time as crews edge by hand, sand migrates, and faces erode. Without a defined buried edge structure, the bunker gradually loses the architect's original line.

Install a defined edge structure around the full perimeter of every bunker.
Use a synthetic edge product, capillary-bound edge, revetment system, or other architect-approved edge treatment.
Anchor the edge so routine edging cannot move the visible boundary outside the structural boundary.
On steep or revetted faces, specify a face-stabilization system rated for the slope angle.

This requirement applies to every bunker, whether or not a floor liner is used.

6. Long-Term Performance

Time	Drainage	Form / Appearance
Day 1	Water moves through the sand to the Drain Box and out the 4-inch main.	Edge system holds the intended bunker line.
Years 1-2	Drainage remains strong because no fabric filter is the primary drain path.	Edge and face structure continue to hold the design shape.
Year 2+ as needed	Drainage remains strong because no fabric filter is the primary drain path.	Edge and face structure continue to hold the design shape.
Ongoing	Actuation helps wash accumulated fines from the sand in place.	Form-retention components continue doing their separate job.

The key difference from conventional construction: reduced drainage is treated as a maintenance event, not a bunker renovation event.

7. Architect Checklist

Test the subgrade at each bunker.
Decide floor treatment per bunker: no liner, permeable liner, or non-permeable liner.
Install an edge/face system at every bunker, regardless of floor treatment.
Locate one SandSave Drain Box at each bunker low point.
Connect each Drain Box to the course drain main with a 4-inch outlet.
Place each Coupler Box out of play and outside the mowing line.
Plan one Mobile Controller for course-wide service.
Design drainage capacity during construction so future liner-based drainage renovation is not part of the expected maintenance cycle.

8. One-Sentence Summary

SandSave lets the architect design the bunker floor for separation, the edge for long-term shape, and the Drain Box for long-term drainage and sand cleaning.