Sta. Rosa environment code, to conserve watershed

STA. ROSA, Laguna, July 28 (PIA) -- The creation of a local Environmental Code is expected to help in the conservation of the Sta. Rosa watershed, the main source of water for four towns in the area.

“The city of Sta. Rosa is the first to legislate an environmental code at the local government unit (LGU) level and we hope that through this, stakeholders will be aware and act together to save the Sta. Rosa watershed from further contamination from untreated sewage and domestic waste,” said Edgardo Tongson, senior consultant of the Water Resources Management at Worldwide Fund for Nature (WWF) Philippines.

The lack of sewage facility and inadequate water management plan threaten the Sta. Rosa watershed and ultimately the Laguna de Bay.

The Laguna Lake covers 24 river basins, one of which is the Sta. Rosa watershed that supplies water to 569,942 households, based on 2007 data from the National Statistics Office.
Spanning a total of 115 square kilometer or 11,500 hectares, the Santa Rosa watershed mainly supplies water to the towns of Sta. Rosa, Biñan, and Cabuyao in Laguna, and in Silang, Cavite, Tongson said.

Silang, although not a part of Laguna, plays an important role in the Sta. Rosa watershed. Tiongson said the town of Silang is the “water recharge area,” where rain falls, becomes surface runoff and sips underground until it reaches the watershed.

From the mountainous Silang, the water sips underground and goes to the three Laguna towns until it reaches the watershed. It is for this reason that Sta. Rosa became an ideal location for an industrial park where corporations such as Asia Brewery, Coca-Cola and other semiconductor industries are located.

As of 2010, NWRB approved agro-industrial permits which would require 178.50 million cubic meters of water per year, which is above the recharge rate of the Sta. Rosa watershed at 106 million cubic meters of water per year, Tongson said.

“The water utility plan for Sta. Rosa watershed exceeds the full capacity of the ground water to meet agro-industrial or domestic needs. Ideally, only 80 percent of the recharge water should be used or we risk undersupply over the next few years,” he said.

In addition, households in Biñan and Sta. Rosa are exposed to contaminated water from the aquifer being tapped by shallow tube wells exposed to contaminants due to location near a toilet or septic tank and tubes running along dirty canals.

A 2008 WWF study identified the 11 of 47 drinking wells sampled in Biñan and 6 of 77 potable wells in Sta. Rosa tested positive for contamination.

The inadequate land use and zoning plan from booming agro-industrial and residential buildings in the area without consideration of the natural waterways prior to construction also makes the area prone to floods.

To address this, Tongson said that developers should build detention ponds that can hold floodwater and dredge selected waterways of silt to increase their carrying capacity.
A good practice of this is in Nuvali, a real-estate in Laguna where four to six percent of the total land area was converted into detention ponds, which now serve as recreational site for boat rides, Tongson said.

He added that the Environment Code is only the first step to get the LGUs involved to talk together and understand that coordination is crucial to preserve the Sta. Rosa watershed and the Laguna de Bay as a whole.

The city government of Sta. Rosa specifically has to partner with nearby Silang town to prevent landowners from selling land to developers since this poses a risk to the recharge capacity of the watershed. (Anna Valmero/ACO, PIA-Laguna)