Water is an essential and vital part to life. For many of us, it is within reach of a faucet, while others are not privy to such a commodity. As human beings, we depend on its good quality and quantity for drinking, recreation, use in industry and growing crops. Many of us, though, are unaware that water is also vital in sustaining the natural systems on and under the earth’s surface.
As more land is being developed on Ambergris Caye, the island is now facing major environmental stress caused by the depletion of fresh ground water. This depletion is creating a high concentration of salinity, not only on our underground water system but in the soil, as well. Symptoms that show that our island is “sick” are everywhere; signs that are telling us that the island is under tremendous stress are clearly visible. You need only to dig a moderately deep hole to detect the unmistakable stench of ammonia, hydrogen sulphide (rotten egg smell) and whirls of methane. These are the tell tale signs of septic conditions below the ground surface of San Pedro.
Research has shown that on Ambergris Caye when it rains, most of the island’s fresh water supply is not allowed to percolate or seep into the ground; therefore it is not recharging or replenishing the earth’s water table. However, not only is our water table not allowed to replenish but the bit of water that is allowed to percolate is not the cleanest, safest and is full of pollutants. Research has also shown that a major contributing factor in these increasing problems is derived from the unsustainable and drastic increase in development. Large structures, buildings and paved surfaces, such as our cobblestone streets, act as a hindrance or barrier that does not allow the fresh water to permeate into the ground. When it rains, most of our water is now drained out of the roads, out of our homes, and out of our potholes into the sea. Although ground water is a hidden and precious resource, its purity and availability are taken for granted. However, gone are the days when one could dig a well and enjoy the purity of our ground water. In San Pedro, it does not take long to dig and reach the water but the water now comes with a bad odor, it is contaminated and unsafe for any use. Nowadays, contamination and accessibility are serious issues and concerns that should be considered. In order to better comprehend the problem; one has to know about the Earth’s water table, the aquifer and understand what roles they play in our supply of fresh ground water? Once it is understood how delicate and simple these systems are, then one can see how development may change our life.
When it rains, water not used by plants moves deeper into the ground. As it seeps into the ground, some of it clings to particles of soil or to roots of plants just below the land surface. This moisture provides plants with the water they need to grow. The water then continues to move downward through empty spaces or cracks in the soil, sand, or rocks until it reaches yet another layer of rock through which water cannot easily move through. This rainwater then fills the empty spaces and cracks above that layer. Below the Island there is a membrane diaphragm layer of calcium carbonate that stretches like a huge blanket. This is known as the “LAJA” and it formed almost 10,000 years ago. This LAJA acts as a receptacle for the fresh water. It is the combination of these two unusual geographical features that allowed 20,000 Mayas to live in Ambergris Caye during the classic period 1400 years ago and today with 18,000 inhabitants.
The top of the water in the soil, sand, or rocks is called the water table and the water that fills the empty spaces and cracks is called ground water. The water table is the level below which the ground is saturated. Any hole in the ground will fill with water when the water-table has been reached. This level often fluctuates with rainfall. The water-table is thus the upper surface of the groundwater. Where the water table meets the land surface, a spring might bubble up or seep from the ground and flow into a lake, stream woodland, or the ocean. Water seeping down from the land surface adds to the ground water and is called recharge water. At least some ground water can be found almost everywhere.
An Aquifer is the name given to underground soil or rock through which ground water can easily move. The amount of ground water that can flow through soil or rock depends on the size of the spaces in the soil or rock and how well the spaces are connected. The amount of spaces is the porosity. Permeability, though, is a measure of how well the spaces are connected.
Aquifers typically consist of gravel, sand, sandstone, or fractured rock such as limestone. These types of materials are permeable because they have large connected spaces that allow water to flow through. The spaces in a gravel aquifer are called pores. The spaces in a fractured rock aquifer are called fractures. If a material contains pores that are not connected, ground water cannot move from one space to another. These materials are said to be impermeable. Materials such as clay or shale have many small pores, but the pores are not well connected. Therefore, clay or shale usually restricts the flow of ground water.
Pollution and depletion threaten ground water
Development can cause serious environmental problems to any island community, to any country and it is causing problems worldwide. According to studies and historians, during the classic period, the Maya civilization used to flourish on the island because of their ability to balance the environment with their development plans. At that time, close to 20,000 people lived in Ambergris Caye, almost the same as today with 18,000. Since then, in a span of a few decades, modern man has placed the environment under so much stress that ignoring the signs is no longer an option. The increase in random mangrove cutting; uni-lateral dredging, the proliferation of piers and the proximity of piers to the reef are key issues that contribute to the depletion of our most precious fresh water resource.
Ground water becomes polluted when toxic substances become dissolved in water at the land surface and are carried down, or leached, to the aquifer with the percolating water. Sometimes ground water contamination occurs naturally, but serious contamination is usually the result of human activities on the land surface. An aquifer provides a plentiful water supply that often attracts a multitude of people to the overlying land. The water is used for such activities as drinking, personal hygiene, residential maintenance, and industrial and agricultural purposes. Many of these activities, however, involve the use and disposal of chemicals which are potential pollutants. When these chemicals are used or disposed of incorrectly, unacceptable amounts can get into the ground water and contaminate it. Since ground water moves slowly, many years may pass before a pollutant released on the land surface above the aquifer is detected in water taken from the aquifer some distance away. Unfortunately, this means that contamination is often widespread before being detected. Even if release of the contaminant is stopped, it may take many years for an aquifer to purify itself naturally.
In some areas, a damaged water table may open an aquifer to an influx of saltwater, impairing or even ruining it as a freshwater source. Not allowing rain water to seep into the ground and “refresh” the underground water also increases the salinity levels. The high concentration of salinity will have many adverse effects, one of them is making the water undrinkable and the other is that it impairs and depletes the growth of trees. No longer can San Pedro grow our crops, the way the island used to thirty years ago. Research has shown that plants with deeper roots can no longer sustain themselves because of the salinity of our underground water. However, plants like our tropical coconut trees can survive because they extract their water from our water table. What will happen when even that gets too salty?
The salinity also affects our marine life. One might think that fish living in the saline oceans aren’t affected by freshwater, but, without freshwater to replenish the oceans they would eventually evaporate and become too saline for even the fish to survive.
In areas already affected by salinity, replanting trees seems an obvious way to solve it. Planting native species, with their ability to grow (and use water) all year round, and to perhaps use water from the water table in times of drought, is certainly one strategy available to land managers and when done on an adequate scale might often be successful. Allowing the water to drain into the ground helps the environment immensely. A bit of mud is unsightly and may ruin your shoes but in the long run it is helping the very environment that we are desperately in need of protecting.
With the continued unsustainable and drastic increase in development on Ambergris Caye, developers must carefully chart the course of its development. According to Omar Mitchell, Consultant for the Ambergris Caye Local Building Authority, developers have a huge responsibility in the way our island will shape up. He stated in an interview with The San Pedro Sun, “We got to look at ways to balance the process out. There is an imbalance on the island when it comes to development and space, as too much structure without being given environmental clearance is placing the island under tremendous stress. We need to find a balance where we can regulate development with the space of the island. One relatively inexpensive way to help with the recharging process is to let the precipitation fall to the ground and let it seep down the soil or the re-planting of deep rooted trees such as palms and coconut trees. Developers must recognize that they are exploiting the island and what would work as a remedial would be the charge Environment Impact Fees.,” ended Mitchell. Many island communities scattered throughout the Caribbean have Environmental Impact Fees, as the one Mitchell suggests. An impact fee is a fee that is implemented by a local government to help reduce the economic burden on local jurisdictions that are trying to deal with population growth within the area.
With Ambergris Caye’s ecology (natural science) threatened, it is urgent that San Pedro residents develop an increased appreciation of the island’s fragile environment and learn to respect and protect it in their daily lives. Sensitizing the public about the environmental issues affecting the community is the only way we can reverse or alleviate the devastating impacts of this phenomenon. With the monies garnered from this impact fee, Mitchell states ACLBA and other environmental agencies will be able to further their monitoring in San Pedro. A presence of these agencies on the island is highly needed and it is one that will assist in the construction boom occurring now in San Pedro. Constant monitoring will be carried out to make sure that developments are abiding by their compliance plans and taking the environment into consideration when constructing.
ACLBA, however clarifies that contractors will not be charged the fee of 0.5% of the value of the building. Compared to other countries, the impact fee is much higher and developers also pay a yearly fee. This impact fee will be a one time deal in San Pedro. San Pedro has open its arms to foreign developers it is only correct that if developers use the beauty of the island and its reef as a marketing feature then the least that can be done is share with the San Pedro community the capital gains and profits made from such real estate transaction. As mentioned before, this money will in turn be used to benefit the entire island, its residents and visitors.