A Master Plan forPark & Wetlands Development and Stream Stabilization in the UP Diliman Lagoon Area: enhancing drainage, water quality, recreation and biodiversity.

Aim: to improve the environmental and built-up conditions of the UP Diliman Lagoon Area and its tributary water bodies by means of the following principal activities:

• channel design improvement for efficient drainage of storm runoff.

• stream habitat-improvement structures for channel stability and biodiversity.

• conversion of ponded areas into re-engineered wetlands for vegetation effects (phytoremediation) to improve the water quality of effluents.

• reclamation of lower marshy areas to provide bank-side park venuesfor enhanced recreational and cultural activities.

• research and demonstration programs and campus-advocacy actions in the affected areas and water bodies.

BE Theatrumand Lagoon Park

Phase-2 Wetlands

Phase-1 Wetlands

CAL CSSP

Univ. Library

Quezon Hall

EnggFilm Center

Univ. Theatre

B.E.

Way

Channel 1

Channel 2

Channel 3

Channel 4

Park Channel

Not to scale

Untreated effluents

Untreated effluents

Psycho Education

NEC Law

treated effluents

Music

Specific designs of channels and wetlands:

1. The cross-sections and type of linings of Channels 1, 3, and 4 shall be redesigned(under Phase 1) in order to accommodate the efficient drainage of maximum storm runoffs (estimated for 5, 10 and 25 years of return period). Tree trunks and geo-textiles shall be utilized as channel lining materials in order to minimize the use of concrete and promote the growth of bank vegetation for stability and biodiversity.

2. Channel 1, carrying the STP-treated effluent plus storm runoff, being steeper than the other channels, will be stabilized (under Phase 1) by means of V cross-vanes (made of boulders, tree trunks and geo-textiles) which are stream-habitat improvement structures aimed at channel stability and attraction of biodiversity through growth of bank vegetation and presence of steps and pools for small animals.

3. The large ponded area in the central part of the Sunken Garden, downstream of the Beta Epsilon Way culvert bridge, and upstream of the Roces Ave. double-barrel circular culvert, shall be converted to a re-engineered (under Phase 2) wetlands in order to improve the water quality of untreated effluents and polluted runoff - coming from various colleges and units: Engg-NEC, Law, Econ, BA, Education, Psycho, CSSP, etc.) – by means of vegetation effects or phytoremediation by selected aquatic plant species.

4. Channel 2 and the upper-half portion of the Lagoon (upstream of the island), which carry the flows from the Roces Ave. DBCC shall be converted to a smaller re-engineered (under Phase 1) wetlands to improve the water quality all incoming effluents and polluted runoff from the upper wetlands (through Roces Ave. DBCC) and various colleges and units: CAL, Film Center, Univ. Theater, Music, etc.

Specific designs of channels and wetlands:

5. Channel 3 shall commence at a suitably located, sized and gated junction box which receives the flow from Channel 1 and also connects with an adjacent reversible-flow gate structure for the regulation of the water level in the re-engineered wetlands in the Lagoon area. Channel 3 can convey the STP treated effluents of Channel 1 to the wetlands during the dry season, whereas Channel 3 can also carry the combined high flows from Channel 1 and the wetlands during the wet season.

6. The re-engineered wetlands in the upper Lagoon area shall have a downstream gated-structure whichallows regulated outflow with improved water quality to a narrower Park Channel which runs through the reclaimed area which is developed as park venues for enhanced recreational and cultural activities.

7. Channel 3 and the narrow Park Channel shall meet finally at the downstream junction from where commences Channel 4 which carries the accumulated flows from the upstream channels and wetlands, with highly improved water quality.

Prepared by: Leonardo Q. Liongson

Topo map and sub-basin boundaries: UPD Academic Oval

Stream Channel Stabilization& Restoration.