NINETEENTH CONGRESS OF THE	
)
REPUBLIC OF THE PHILIPPINES	
)
First Regular Session	
)
HOUSE OF REPRESENTATIVES
House Bill No. _______
Introduced by REPRESENTATIVES LANI MERCADO-REVILLA, 
BRYAN B. REVILLA AND RAMON JOLO REVILLA III
AN ACT
MANDATING THE ESTABLISHMENT, MANAGEMENT, MAINTENANCE, AND 
REGULATION OF A RAINWATER HARVESTING FACILITY IN ALL NEW 
INSTITUTIONAL, COMMERCIAL, INDUSTRIAL, AND RESIDENTIAL 
DEVELOPMENT PROJECTS IN METRO MANILA
EXPLANATORY NOTE
There is a looming water crisis, but as correctly pointed out by President 
Ferdinand Marcos Jr.: “We all know the Philippines is not a dry place, and why do we 
not have enough water?” 
1
Water is a scarce resource. Nevertheless, we have ample rain falling in the 
country. The Philippines receives around 2,400 millimeters of rainfall each year, but 
the country only harvests 6% of that rainfall. India, on the other hand, harvests 
around 60% of the 700-millimter rainfall per year.  Evidently, the Philippines is unable 
2
to maximize its abundance of rain.
Aside from India, rainwater harvesting is also being widely practiced in 
countries such as Singapore, Japan, Germany, and Australia. 
 Speech by President Ferdinand R. Marcos Jr. at the Opening and Ribbon-cutting Ceremony of the 6th Edition of 
1
the Water Philippines Conference and Exposition, published by the Presidential Communications Office – 
Presidential News Desk on March 23, 2023.
 According to former Agriculture Secretary William Dar during a farmers’ forum held on September 20, 2019 in 
2
La Trinidad, Benguet, cited in “Rainwater harvesting seen as solution to water scarcity”, published by the 
Department of Agriculture Communications Group on September 21, 2019.
May 16, 2023
2:54 pm
8148




NINETEENTH CONGRESS OF THE	
)
REPUBLIC OF THE PHILIPPINES	
)
First Regular Session	
)
HOUSE OF REPRESENTATIVES
HOUSE BILL NO. _______
Introduced by REPRESENTATIVES LANI MERCADO-REVILLA, 
BRYAN B. REVILLA AND RAMON JOLO REVILLA III
AN ACT
MANDATING THE ESTABLISHMENT, MANAGEMENT, MAINTENANCE, AND 
REGULATION OF A RAINWATER HARVESTING FACILITY IN ALL NEW 
INSTITUTIONAL, COMMERCIAL, INDUSTRIAL, AND RESIDENTIAL 
DEVELOPMENT PROJECTS IN METRO MANILA
Be it enacted by the Senate and House of Representatives of the Philippines in 
Congress assembled:
SECTION 1. Short Title. This Act shall be known as the “Rainwater 
Harvesting Facility Act.”
SEC 2. Declaration of Policy. It is declared a policy of the State to protect 
the right of the people to a balanced and healthful ecology and advance the health 
and welfare of its citizens in accordance with the rhythm and harmony of nature. 
Pursuant thereto, the government and all its instrumentalities shall systematically 
integrate the concept of climate change in the various phases of policy formulation 
and development planning, in drawing up and implementing poverty reduction 
strategies and innovations that provide beneficial effects to the greatest number of 
people with the least cost and negative externalities. 
In this light, and given the demands of a growing population, the State shall 
adopt measures and strategies in order to efficiently conserve water and help attain 
8148


water security. Among other strategies on water conservation, rainwater harvesting 
facilities shall be established not only to conserve the supply of potable faucet water 
but also to prevent flooding in communities that sometimes result into devastating 
effects to human life and property. Both the public and private sectors are urged to 
actively participate in flood mitigating efforts and initiatives of the government.
The State recognizes Metro Manila as one of the densest areas in the 
country. To mitigate the adverse effects of continuing growth in population and 
human settlements, the State shall ensure that Metro Manila local governments are 
capacitated to respond to threats wrought by natural calamities and disasters such 
as massive flooding. Towards this end, the State shall mandate the construction of 
rainwater harvesting facilities in all new public and private commercial, institutional, 
and residential developments in Metro Manila which will serve as a pilot area from 
which other similar areas can learn.
Pursuant thereto, owners and developers of all new public and private realty 
development projects in Metro Manila requiring the issuance of building permits are 
mandated to design and construct a rainwater harvesting facility to prevent or delay 
the release of rainwater and runoff water into the public drainage systems, creeks, 
and natural waterways.
SEC. 3. Purpose. This Act seeks to establish minimum rainwater 
management requirements and controls to protect and safeguard the general health, 
safety, and welfare of the public against the ill effects of floods on one hand, and 
water shortage on the other. This Act pursues the following objectives:
a) Reduction of flooding, siltation, increases in stream temperature and 
stream bank erosion, and maintain the integrity of stream channel by 
regulating the accumulation of rainwater runoff in any proposed and 
existing commercial, institutional, industrial, and residential developments;
b) Prevention of the degradation of water quality by averting non-point source 
pollution caused by rainwater runoff developments;
c) Regulation of the annual volume of surface water runoff from any specific 
site during and following a development so as not to exceed the pre-
development hydrologic regime in an area; and
d) Establishment of standards for rainwater management control to ensure 
that these and the facilities thus built are properly complied with and do not 
pose without a threat to public safety.
SEC. 4. Definition of Terms. As used in this Act:
a) Applicant – refers to a property owner or agent who has filed an 
application for a rainwater management permit;


b) Building – refers to any structure built for the support, shelter, or enclosure 
of person, animals, chattels, or moveable property of any kind and which is 
permanently affixed to the land;
c) Building Official – refers to a local building official as appointed or 
designated pursuant to Presidential Decree (PD) 1096, or the National 
Building Code of the Philippines (NBCP); 
d) Certificate of Occupancy – refers to a permit issued by the Zoning Officer 
indicating that the use of the building or land is in conformity with the 
Zoning Ordinance or that there has been a legal variance therefrom;
e) Channel – refers to a natural or artificial watercourse with definite bed 
banks that conducts flowing water continuously or periodically;
f)
Contour interval – refers to the vertical distance between the elevations 
represented by adjacent contour lines on a map;
g) Contour line – refers to a line on a map or chart connecting all points of 
the same elevation or depth in a particular area;
h) Detention – refers to a rainwater management practice of temporarily 
storing rainwater runoff to control the peak discharge rate and to likewise 
induce settling of pollutants through gravity;
i)
Developer – refers to a person or entity who undertakes land disturbance 
or land development activities; a developer may only be contracted to 
develop and may or may not be the owner of the development, such as a 
building structure being built;
j)
Development – refers to any man-made change to improved or 
unimproved real estate, including buildings or other structures, mining, 
dredging, filling, grading, paving, excavation, or drilling operation;
k) Flood frequency – refers to a record of past flood events or occurrences 
that yield flood data estimates used principally to compare expected 
changes in flood damages with the economic and social costs or benefits 
guiding a contemplated action;
l)
Hydrologic regime – refers to the quantity and dynamics of water flow or 
the variations in the state and characteristics of a water body depending 
on location and time of the year, which may occur in regular patterns; 


m) Infiltration – refers to the process of percolating or gradually filtering 
rainwater into the subsoil;
n) Infiltration facility – refers to any structure or device designed to infiltrate 
water to the subsurface. These facilities may be above ground or below 
ground;
o) Land disturbance - refers to any activity which changes the volume or 
peak flow discharge rate of rainfall from the land surface. This may include 
grading, digging, cutting, scraping, or excavating of soil, placement of fill 
materials, paving, construction, substantial removal of vegetation, or any 
activity which bares soil or rock or involves the diversion or piping of any 
natural or man-made watercourse;
p) Landowner – refers to the legal or beneficial owner of land, including those 
holding the right to purchase or lease the land, or any other person holding 
proprietary rights over the land;
q) Off-Site facility – refers to a rainwater management installation located 
outside the subject property boundary described in the permit application 
for land development activity;
r)
On-Site facility – refers to a rainwater management measure located within 
the subject property boundary described in the permit application for land 
development activity;
s) Rainwater Design Manual – refers to the Planning and Design Manual for 
the Control of Erosion, Sediment, and Rainwater of the Department of 
Public Works and Highways;
t)
Rainwater management – refers to the use of structural or non-structural 
practices that are designed to reduce rainwater runoff pollutant loads, 
discharge volumes, and peak flow discharge rates;
u) Rainwater retrofit – refers to a rainwater management practice designed 
for an existing development site that had not implemented rainwater 
management measures, or had previously implemented measures that 
were inadequate to meet the rainwater management requirements of the 
site;
v) Rainwater runoff – refers to water flow on the surface of the ground, 
resulting from precipitation;


w) Rainwater treatment – refers to a process by which collected rainwater is 
filtered or cleaned through either structural or non-structural means to 
prevent or reduce point source or nonpoint source pollution inputs to 
rainwater runoff and water bodies, as well as to upgrade rainwater for 
reuse;
x) Rainwater Harvesting Facility – refers to a flood control structure such as a 
vertical detention tank, horizontal water tank, open retarding basin, and 
multi-water catchment area, or an on-site regulation pond used to prevent 
or delay the release of rainwater into the public drainage system;
y) Return period – refers to the average length of time in years for a rain-
related natural disaster of given magnitude to be equated or exceeded by 
the length of time that a rainwater-related disaster may probably recur;
z) Recharge – refers to the replenishment of underground water reserves;
aa)Redevelopment – refers to any construction, alteration or improvement 
exceeding one hundred (100) square meters in high density areas where 
existing land use is for commercial, industrial, institutional, or multi-family 
residential purposes;
bb)Stop Work Order — refers to an issuance by the Building Official that 
requires the discontinuance or stoppage, in part or whole, of the 
construction activity in a site due to a violation of the law;
cc) Watercourse — refers to a permanent or intermittent stream or other body 
of water, either natural or man-made, which gathers or carries surface.
SEC. 5. Rainwater Harvesting Facility Requirement. A project owner or 
developer of a new commercial, institutional, industrial, and residential development 
project in Metro Manila, with a building footprint area of at least one hundred (100) 
square meters that requires the issuance of building permit, shall reserve, develop, 
and maintain a rainwater harvesting facility with a minimum storage tank size in 
cubic meters calculated by dividing the building footprint area by seventy-five (75).
The owner or developer of an ongoing development project in Metro Manila, 
that has no existing provision for rainwater harvesting shall build a facility within a 
period of three (3) years from the effectivity of this Act, or suffer the penalty imposed 
in Section 13 hereof.
When additions, alterations, conversions, and renovations of an existing 
building constructed after the effectivity of this Act fit within the minimum building 
footprint, the whole building shall be subject to the applicable provisions of this Act.


To conserve potable water, rainwater collected by a harvesting facility may be 
used for non-potable and suitable purposes, such as gardening and air-cooling 
processes, provided through a distinct and separate piping system from the potable 
water supply system. The landowner or developer may opt to utilize a system or 
technology that can recycle collected rainwater for potable uses such as bathing, 
dishwashing, or cooking, provided it meets the water quality standard of any 
government water agency or duly accredited water testing center.
SEC. 6. Requirements for Rainwater Management Plan. All project owners 
or developers of proposed commercial, industrial, and residential development or 
any residential multi-dwelling units of more than One Thousand square meters (l,000 
sqm) land area must submit a Rainwater Management Plan (RMP) as part of the site 
development application and approval process.
The RMP shall include the following information:
a) Description of existing conditions in the location of the development site:
i)
Topographic map with one (1.0) meter minimum contours line or an 
appropriate contour interval of the land proposed for development 
or redevelopment;
ii) Location of natural waterways including banks and centerline of 
streams and channels;
iii) Normal shoreline, coastlines, outline of lakes, natural depressions 
and ponds, including drainage flow lines; and
iv) Quantification of flows (discharge and volume) in its natural 
condition.
b) Proposed Site Development Plan (SDP) in an appropriate scale and size 
showing the following:
i)
Retention/detention basins and lines of inflow and outflow;
ii) Location, size, and slope of rainwater conduits and drainage 
swales;
iii) Rain, sanitary, and combined sewer and outfalls; and
iv) Delineation of upstream and downstream drainage features and 
watersheds which might be affected by the development; and


v) Other environmental features including limits of wetland areas, 
green buffers, planting strips, and any designated natural areas for 
rainwater management.
c) Description of the Proposed Rainwater Management System (RMS) to 
safely and completely manage rainwater runoff onsite or offsite, help 
maintain the natural hydrologic cycle and condition of flow in a locality, and 
reduce the risk of downstream flooding.
The proposed RMS shall be accompanied by hydrologic and hydraulic 
calculations to adequately demonstrate the effectiveness of the RMP. It 
shall be designed to meet the desired flood frequency which is designated 
to a particular drainage structure as stated in the Design Manual of the 
DPWH: Provided, That a 25-year flood frequency or higher may be 
required for major rivers and waterways, subject to the design criteria in 
Section 9 of this Act.
The RMP shall be accompanied by relevant information such as rainfall 
data in a locality, maps, and other descriptive material to include the 
following:
1) The extent of catchment and drainage channels on site, and direction 
of the flow of the channels including the final outfall of the discharge 
from the site;
2) Hydrologic and hydraulic design calculations for the pre-development 
and post development conditions of a rainwater management system 
as required under Section 9 hereof. The calculations for determining 
peak flows include a description of storm frequency, intensity, duration, 
time of concentration, soil curve number or runoff coefficients, peak 
runoff rates and total runoff volumes, infiltration rates, culvert 
capacities, flow velocities, data on the increase in rate and volume of 
runoff for the design storm; and
3) Technical specifications of the proposed RMS, including a description 
of proposed rainwater conveyance practices on-site, existing off-site 
rainwater conveyance systems including receiving streams, channels, 
and outfall and inlet locations, and elevations of locations and high-
water elevations.


SEC.7. Chemicals, Effluents, and Other Contaminants. Prior to the 
issuance of a building permit for their development or re-development, all industrial 
plants and estates shall secure the appropriate certification from the Department of 
Environment and Natural Resources that all chemicals used in their operations, their 
by-products, effluents, and other operational discharges do not contain harmful 
contaminants that can be washed by or into the rainwater.
The type of roofing must also be identified and assessed if used for collecting 
rainwater as some roofing materials may seep chemicals that can cause adverse 
effects if ingested, used in irrigation, fishponds, groundwater recharge, among 
others.
SEC. 8. Utilization of Rainwater. Rainwater shall be harvested for the 
following uses:
a) Rainwater for urban irrigation. – Due to the high cost of Class A water, its 
use for yard irrigation shall be minimized if not prohibited and instead, 
water for irrigation shall come from the rainwater detention system. 
Rainwater as source for urban irrigation or watering of lawns shall be 
indicated in all development plans. Treated grey water from effluent of 
treatment facility may be a secondary source of water for urban irrigation.
b) Rainwater for groundwater recharge. – The RMS is intended mainly to 
ensure natural balance of the hydrologic cycle by allowing rainwater to 
recharge the groundwater table that sustains the yield and production of 
deep wells. Groundwater table recharging may be in the form of the 
following management systems:
i)
Lagoon or retention pond that allows for natural seepage to the 
ground water aquifer;
ii) Swales and depression storage;
iii) Porous or paver blocks on some developed areas;
iv) Retention channels
The sizes and dimensions of any of the above facilities shall be 
dependent on the rainfall intensity and the size of the development.


c) Rainwater for firefighting. – Rainwater may substitute or augment the 
firefighting requirement, subject to health and corrosion standards. A 
separate storage tank for fire water reserve shall be constructed. Other 
laws concerning the requirement of water for firefighting shall be 
considered.
d) Rainwater for construction. – Simple filtration systems and other applicable 
methods to remove suspended solids and other coarse materials may be 
employed to improve water quality and avert adverse effects to 
construction equipment and the environment.
e) Rainwater for other non-potable water supply. – Rainwater shall be 
subjected to primary and secondary treatment to make it a viable 
secondary source for the following purposes:
i)
Washing of cars, floor yards;
ii) Flushing of toilet (water quality should meet certain standard to 
avoid discoloration of fixtures); and
iii) Fish ponds, aquarium and the like.
f)
Rainwater for potable uses. – To make it potable, rainwater may be 
collected, processed, subjected to filtering innovations or technological 
interventions, and used for drinking, cooking, dishwashing, and bathing, 
subject to water standards. 
Potable water quality shall at all times comply with the requirements and 
standards of the Philippine National Standard for Drinking Water 
(PNSDW).
g) Rainwater for ecological requirements. – Seasonal fluctuation of rainfall 
affects the rain flora and fauna of waterways. Rainwater runoff shall 
therefore be managed properly to allow steady release of water to 
waterways, thus, ensuring the continued supply of water.
SEC 9. Preparation of the Rainwater Design Manual. – The Department of 
Public Works and Highways (DPWH) shall prepare the Rainwater Design Manual 
(RDM) which must provide, among others, information on the following: (I) 
conveyance system of the rainwater harvesting facility, (2) make of the rainwater 


retention facility, (3) management of rainwater discharge to control flooding, (4) 
protection of the local water bodies from pollution through rainwater discharge 
treatment, (5) dike or bank protection for water bodies receiving rainwater discharge, 
and (6) utilization options for collected rainwater.
The RDM shall contain the following guidelines:
a) All sites shall establish a rainwater management system to control the 
peak flow rates of rainwater discharge and to allow the RMS facility to treat 
collected rainwater for both water quality and quantity. Peak post-
construction rainwater runoff should not exceed peak pre-construction 
rainwater runoff from the site to the greatest extent possible;
b) All rainwater runoff generated from any development shall not discharge 
untreated rainwater directly into a jurisdictional wetland or local water body 
without adequate treatment;
c) A structural and non-structural Rainwater Treatment System (RTS) shall 
be designed to treat the first twenty (20) millimeters of rainwater runoff. 
Thus, for every one (l) hectare of new development, a two hundred (200) 
cubic meter detention or retention tank shall be constructed to minimize 
flooding and improve water quality. Sanitary wastewater treatment facilities 
shall be designed and installed to comply with existing health regulations 
and the effluent standard of the DENR;
d) Untreated sanitary waste shall not be discharged to waterways and land 
surface without proper treatment and shall not come in contact with 
rainwater runoff. The discharge of treated effluent to water bodies shall be 
in accordance with the river classification. For unclassified rivers and water 
courses, effluents should meet the Class C water category. To be 
discharged to an urban drainage system, effluents should meet the Class 
D water category. In all cases, the prescription provided by the DENR shall 
be followed;
e) To protect stream channels from degradation, the velocity of runoff water 
shall be limited to less than one (1.0) mls, otherwise, bank protection shall 
be provided;


f)
Rainwater discharges to critical areas with sensitive resources (including 
shellfish beds, swimming areas, water supply reservoirs and groundwater 
recharge areas) may be subject to additional performance criteria and 
management restrictions;
g) Rainwater discharges from land uses or activities with higher potential 
pollutant loadings, known as “hotspots”, must be in accordance with the 
specific structural and pollution prevention practices;
h) Rainwater storage and drainage systems must be secured from mosquito 
breeding and those of other similar insects that may endanger public 
health;
i)
Prior to designing the RDM, an applicant for a building permit must consult 
with the Building Official to determine compliance with additional rainwater 
design requirements;
j)
For existing development or developed areas, the rainwater management 
system requirement must be imposed on the following conditions:
1) The owners of existing or old developments shall submit to the 
concerned building officials the technical design of existing rainwater 
management system to demonstrate its contribution to flood control 
and mitigation and the rainwater management program;
2) The total required storage volume of rainwater may be the 
cumulative volume stored from various sources such as cistern, 
lagoon onsite or offsite, and a depression storage; and
3) That at least 50% of the required volume shall be met within five (5) 
years from the effectivity of this Act.
The Department of Public Works and Highways, Department of Human 
Settlements and Urban Development (DHSUD), Department of Environment and 
Natural Resources, and local government units (LGUs) shall require the 
incorporation of a Rainwater Management System in the design of all new 
commercial, institutional, industrial, and residential development projects in Metro 


Manila. The LGUs shall ensure that these facilities are built during the construction 
phase of the projects.
In formulating the design manual, the DPWH shall consult the experts or the 
Department of Science and Technology (DOST) and DENR on requirements that 
entail scientific bases or study.
SEC.10. Construction Inspection.
a) The applicant for a building permit must notify the concerned building 
official in advance before the commencement of construction;
b) All applicants for a building permit for commercial buildings and multi-
family residential buildings over four (4) units are required to submit actual 
drawings of the rainwater management facilities located on-site after final 
construction. The rainwater facility plan must show the final design 
specification for all rainwater management facilities and must be certified 
by a licensed engineer. A final inspection of the rainwater facility is 
required before the release of any performance security, performance 
bond, or guaranty between the owner or developer of the contractor or 
builder;
c) The City or Municipal Engineer shall inspect all drainage facilities while 
under construction. When facilities are not constructed according to 
approved plans the local government unit (LGU) shall require the project 
owner or developer to make the necessary corrections. All drainage 
facilities, whether or not these are owner by or assigned to the LGU, 
located on private property, shall be accessible at all times for inspection 
by the City or Municipal Engineer or other responsible public official;
d) The City or Municipal Engineer shall inspect all sanitary waste treatment 
facilities while under construction of building and upon completion to 
insure proper installation and connection to waste water collection systems 
when applicable. The City/Municipal Engineer shall ensure that sanitary 
waste treatment facilities are properly functioning before issuing the 
required certificate of occupancy.
Any contracted architect or civil engineer employed by the owner or developer 
to plan and supervise the construction of the facility shall not be precluded from 
inspecting the construction work to check and determine compliance with the plans 
and specifications of the building, pursuant to the provisions under Inspection and 
Supervision of Work or Section 308 of the National Building Code of the Philippines.


SEC. 11. Maintenance and Repair of Rainwater Facilities. The owner or 
developer is expected to perform regular maintenance and repair of the rainwater 
facility whenever necessary to make sure that this is in working condition, safe for 
public use and the environment. At the minimum, the following must be undertaken: 
(1) visual inspection and cleaning of the facility after major rain events, (2) regular 
clearing of all sediments, silts, and debris, (3) drainage clean-up, and (4) 
replacement of filters and insect screens as necessary.
In addition, the owner or developer shall comply with the following 
requirements:
a) All rainwater management facilities must undergo a yearly or regular 
inspection process at a frequency sufficient to determine the functioning 
ability of the conveyance system and any repair needs; this shall include 
inspection prior to the beginning of the Typhoon Season or any forecasted 
major rains that may equal the design requirements, and after any major 
rain events; 
b) All drainage and sanitary waste treatment facilities located on private 
property, whether dedicated to the LGU or not, shall be accessible at all 
times for inspection by the City/Municipal Engineer or other responsible 
public officials, especially when there is reason to suspect that a 
malfunction has resulted in rainwater runoff pollution by unsanitary wastes;
c) Depending on the type of facility, mosquito or insect screens must be 
replaced as necessary to avoid infestation or breeding ground for 
pathogens;
d) Parties responsible for the operation and maintenance of a rainwater 
management facility shall make and keep records of the installation, 
maintenance, and repairs, and shall retain these records for at least five 
years. These records shall be made available to the City or municipality 
during inspection of the facility and other reasonable times upon request;
e) The concerned Building Official shall notify the owner of a rainwater facility 
in writing that maintenance work is required on it. The owner will have sixty 
(60) days from the receipt thereof to ensure that the facility is in proper 
working condition.


SEC. 12. Reportorial Requirements. The DPWH shall require the owner or 
developer of all new commercial, institutional, industrial, and residential development 
projects to submit a compliance report within twelve (12) months from the date of the 
completion of the project.
The DPWH shall henceforth require the building owners covered under 
Sections 5 and 6 of this Act to submit an annual report of the performance of such 
rainwater retention facility which may include information on the total volume of 
retained rainwater and its utilization.
SEC. 13. Enforcement and Penalties.
a) Any person found to be in violation of any of the provisions of this Act shall 
be guilty of a misdemeanor and shall be penalized with a fine not to 
exceed Fifty Thousand Pesos (Php50,000.00) or imprisonment for no 
more than ninety (90) days, or both. A continuance of a violation without 
reasonable effort on the part of the violator to correct the same shall 
constitute a new and separate offense each day;
b) In the case of a partnership, association, corporation, or any juridical 
person, the penalty shall be imposed upon the president, treasurer, or any 
other officer or person responsible for the violation;
c) If the offender is a foreigner, the foreigner shall be deported immediately 
without further proceedings after payment of fine;
d) If the concerned Building Official shall find that any provision of this Act is 
violated, the person responsible for such violation shall be notified in 
writing, about the nature of the violation and the proper action necessary 
to correct it, such as the discontinuance of any construction on site.
SEC. 14. Incentives. Landowners or developers of existing structures built 
prior to the implementation of this Act who may opt to install a rainwater harvesting 
system or a rainwater retrofit in accordance with this law shall receive a realty tax 
incentive from the local government which may be in the form of a tax discount of not 
less than three percent (3%) per annum over and above the regular discount 
provided by the local government. An additional two percent (2%) tax discount per 
annum will be granted to those who will invest in any innovation or a technology that 
will recycle collected rainwater for potable uses within the standard prescribed by 
law.


SEC. 15. Obligation of the Regulatory Agencies. The DPWH, DENR, DOST, 
LGUs, their sub-agencies, and subsidiaries are mandated to provide full assistance 
to every project owner or developer covered in this Act in order that the requirements 
and standards prescribed herein may be properly executed in the design and 
construction of rainwater harvesting facilities. Agency assistance shall include proper 
advice, technical guidance, provision for needed data and facilitation of required 
documents. As much as practicable, all technical and documentation requirements 
must be at zero to minimal cost to the applicant project owner or developer who shall 
establish, manage, and maintain a rainwater harvesting facility.
SEC. 16. Implementing Rules and Regulations. Within sixty (60) days from 
the effectivity of this Act, the Secretary of Public Works and Highways shall, in 
coordination with the Secretary of the Interior and Local Government, Secretary of 
Environment and Natural Resources, Secretary of Human Settlements and Urban 
Development, and Secretary of Science and Technology, promulgate the rules and 
regulations for the effective implementation of this Act. The implementing rules and 
regulations shall include the standards and guidelines for the design, construction, 
installation, materials, site selection and planning, site-specific considerations, and 
maintenance of the rainwater harvesting facility.
SEC. 17. Separability Clause. If any provision or part of this Act is declared 
invalid or unconstitutional, the remaining parts or provisions not affected shall remain 
in full force and effect.
SEC. 18. Repealing Clause. All other laws, rules and regulations, orders, 
circulars, and other issuances or parts thereof, which are inconsistent with the 
provisions of this Act are hereby repealed, modified, or amended accordingly.
SEC. 19. Effectivity. This Act shall take effect fifteen (15) days after its 
publication in the Official Gazette or in at least two (2) newspapers of general 
circulation.
Approved,