By Michelle Domocol @inflourish_
Back to Inflourish: Cebu Blog
Last August and most of September we experienced a terrible heatwave and extended drought. We are thankful the rains have returned. Much of Cebu’s water supply are vulnerable to unpredictable heatwaves and droughts due to declining groundwater reserves. Excessive extraction of groundwater, waterway pollution, and intensive irrigation has threatened our water supply. Additionally, the mass construction of impervious surfaces worsens our groundwater crises. Pouring cement over every urban surface stops rain from naturally seeping into our soils and refilling groundwater.
During August, Healing Present’s forest shrubs and gardens suffered from dehydration. Luckily, our water conservation methods from previous years delayed plant dehydration and help plants recover. Our water reserves also helped us maintain supplies for daily cooking, bathroom, and property maintenance activities. Our water saving and storage include above ground water tanks, retention ponds, mulching, and groundcover. We plan to add percolation pits, recharge ponds, and drought-resistant groundcover. Here are some of the main features of our water management techniques. Perhaps you want to protect your land, family, or community from seasonal water shortage. This may inspire you to integrate methods that maximize rainwater storage and groundwater recharge during wet/typhoon seasons.
Groundcover & Vegetation
Groundcovers are low-growing plants that can spread quickly and cover bare soil. Vegetation like shrubs and trees to catch rain and replenish water supplies. As their leaves and root networks increase, they soften the impact of rainfall and hold soil together. They also help soil absorb storm water and refill groundwater. During rainstorms that means less water erosion and no land slides. Groundcover can also keep the soil moist. The special reserve of moisture helps plant roots survive droughts and recover when rain returns. Here are some examples of groundcover we use on the farm:
Retention and Recharge Ponds
Retention Ponds collect rainwater throughout the year and are constructed with a cement or plastic pond liner. The liner is a barrier to prevent water seep from seeping down into the soil. If our above ground water tank supply or groundwater levels were low, we could pump water from these ponds. In contrast, recharge ponds do not have a liner. They are seasonal dug-out ponds that store rainwater during the wet season. In Healing Present, these ponds can replenish forest roots, springs in underground caverns, and groundwater.
Inspired by recharge ponds in South Asia, these recharge ponds are built in sloping or low-lying areas. Like the groundcover technique, they protect us from unstable soils and landslide damage. The ponds are surrounded by groundcover, shrubs and trees to increase rainwater absorption. Combing techniques ensure rainwater is not wasted or running off the property and causing flood damage. Below is an example of a standard recharge pond:
Percolation Pits
Percolation pits are special rainwater drainage basins. They filter surface runoff and stormwater before it refills groundwater. Percolation pits are built in areas with a high rainfall absorption and permeable soil. You can install percolation pits next to buildings so they receive water from roof gutters and rainwater drainage pipes. Or you can place them in the middle of gardens and forests on sloping areas with high rainfall. When choosing a location make sure you test the water infiltration and percolation rate of the soil. Simple soil tests determine if rain would easily travel from through the percolation pit layers, down into the native soil, and towards groundwater. Below is a diagram of a percolation pit:
I hope this inspires you to find stormwater solutions and water saving methods. Positive changes can preserve water supplies and divert pressure off our finite groundwater reserves.
