A spring box will gather and keep water from contamination and may increase its flow. There are two cement designs for spring box construction, dependent on the incline or flatness of the earth. One has a permeable side section for collecting water and the other has a permeable bottom for use on level terrain. Both are constructed using the same method with different openings for water input. To ensure a reliable source, build a spring box in the peak dry season.
Locate the "eye" of the spring; this is the single flowing source. Dig into the ground and watch the increase or decrease of the flowing water to determine if you have a single flow.
Dig until you get to an impervious layer of soil.
Lay rocks and gravel against the spring to prevent erosion and provide some sedimentation. Water will flow through this layer before it gets into the spring box.
Rake the ground level and smooth.
Dig a diversion ditch 8 metres (about 26 feet) uphill from the spring location. Angle this ditch so that runoff water will go around the spring box location.
Build wooden forms; the size depends on the spring, location and desired capacity. These forms will hold the cement in place as it dries for seven days. Make the outside forms 10 cm (4 inches) bigger than the inside spring box and suspend the inside form 10 cm (4 inches) higher than the ground level. Leave the area where you placed the holding layer of rocks and gravel open to this source.
Drill 2 cm (3/4 inch) holes in the forms for the overflow and outlet pipes. Place the lower outlet hole 25 cm (10 inches) from the bottom of the forms and the overflow hole just below the water level. Put temporary 2 cm (3/4 inch) plastic piping in these holes.
Brace the forms on the inside to keep them separate. Drill small holes and insert wire. Tighten this wire by twisting with a sturdy stick that is stuck into the centre of the wire and turn to clamp the wire to the wooden forms; they should be kept 10 cm (4 inches) apart.
Add temporary braces to the outside of the wooden forms to keep them from slumping as the wet cement is added. These are pieces of wood placed diagonally from the outside form walls to the ground. These can be pieces of lumber or small trees.
Oil the inside walls of the form with motor oil. This will keep the cement from sticking to the forms as it dries.
Mix cement in proportions of 1 part cement, 2 parts sand and 3 parts gravel. Add small amounts of water to obtain a consistency of thick mud -- too much water makes weak cement. A wheelbarrow is a good cement-mixing container; use a hoe for stirring.
Shovel the cement into the forms and tamp it as you go to eliminate any air pockets. Tamping is accomplished by hitting the sides with a hammer or rock.
Add 10 cm (4 inches) of cement to the floor of the box if the spring is the permeable side version. This will create an impermeable seal between the box and the ground. Keep the bottom of rocks and gravel if your location dictates a bottom feeding spring box.
Make a cement cover with a convex top to help shed water away from the spring box. Reinforce this shape and add metal handles
Cover all new cement with wet burlap for seven days to insure proper curing. If cement dries too quickly, it will not create a strong bond.
Slope all the earth, on all the sides of the spring, away from the box to divert any surface water.
Remove the temporary pipe pieces and insert permanent piping and seal to prevent leaks.
Put plastic or copper screening over the pipe openings.
You can use reinforcing materials, especially around the edges of the box, to keep them from cracking. Fence around the perimeter of the spring to keep animals away from this area. Disinfect spring boxes once a year with a chlorine solution of 0.2 litres (1/3 pint) of bleach to 10 litres (2 gallons) of water.
Tips and warnings
- You can use reinforcing materials, especially around the edges of the box, to keep them from cracking.
- Fence around the perimeter of the spring to keep animals away from this area.
- Disinfect spring boxes once a year with a chlorine solution of 0.2 litres (1/3 pint) of bleach to 10 litres (2 gallons) of water.