The Civil Engineering and Development Department (CEDD) of the Hong Kong SAR has identified Kwu Tung North and Fanling North as one of the New Development Areas (KTN/FLN NDA) in the Northern Metropolis to meet long-term housing demand and stimulate economic growth. Prioritizing ecological integrity and conservation, CEDD, along with the Agriculture, Fisheries and Conservation Department (AFCD), green groups, including the Conservancy Association (CA) and the Hong Kong Bird Watching Society (HKBWS), ecologists, farmers and AECOM, has transformed some 37 hectares of ecologically valuable land into the Long Valley Nature Park (LVNP), a key component of the KTN/FLN NDA. This park exemplifies the multiple benefits nature-based solutions can bring to urban developments: enhancing biodiversity, preserving important cultural landscapes, and maintaining local food production while providing a valuable green space for community recreation and education.

AECOM has been tasked with providing comprehensive services including design and construction, environmental consultation — especially in ecology, landscape and water quality — building construction and park planning.

Our solution to conserve ecologically important environment and preserve sustainable agricultural practices in LVNP:

Biodiversity Zone (~21 ha)• Area of wetland increased by ~8 hectares through the conversion of dry agricultural land and abandoned farmland into wetlands
• Various types of wetland habitats are provided for foraging, sheltering and breeding of birds and other wildlife
Agriculture Zone (~11 ha)• Comprises various types of fields and maintains an open field for commercial farming using eco-friendly or organic farming methods
Visitor Zone (~5 ha)• Provides facilities including an outdoor classroom and bird hide to appreciate the wetland ecosystem in proximity
• Offers a space for workshops and activities to enhance the public’s understanding of Long Valley’s significance

Enriching biodiversity and sustainable features

The LVNP revives underutilized farmlands into diverse wetland habitats, providing a haven for various wetland species to forage, take shelter, and breed. The mosaic pattern design of farmlands enables an even distribution of habitats throughout the park. As a result of revitalization efforts, the wetland area of the LVNP has expanded by 8 hectares, making it an enticing habitat for both native and migratory birds. Notably, the park now hosts critically endangered birds such as the yellow-breasted bunting, further enriching Long Valley’s biodiversity landscape.

Achievement in biodiversity enhancement at LVNP within the project period*:

Additionally, irrigation water for Long Valley, sourced from the Sheung Yue River, is now being naturally improved by our innovative water treatment wetland. This wetland includes a sedimentation pond, a macrophyte zone, and an open water zone. The process begins with the river water entering the sedimentation pond, where a controlled flow velocity allows coarse materials to settle for easy collection and removal, providing initial purification.

The water then flows through a vegetated macrophyte zone that filters particulates and soluble pollutants. Finally, it passes through the open water zone, where exposure to sunlight naturally disinfects the water, effectively reducing pathogens. This sustainably treated water is then utilized for irrigation in the Agricultural and Biodiversity Zones.

Achieving carbon reduction through green initiatives

The Long Valley Nature Centre, a new addition to the park, serves as an educational hub on Long Valley’s ecological significance. Embodying sustainability, the center is designed as a “green” building by adopting a variety of green features such as the use of recycled materials for the exterior surfacing, an efficient air conditioning system, low-power lighting solutions, photovoltaic panels that target to achieve over 32 percent in annual energy savings, and adoption of rainwater harvesting recycling facilities. The center has received BEAM Plus Provisional Platinum rating from the Hong Kong Green Building Council for its eco-friendly design.

Building resilience against climate change

To combat climate change and address Long Valley’s existing irrigation and flooding challenges, we designed a 1.9 kilometer irrigation channel to enhance the irrigation supply and drainage network in LVNP. The design features gabion units to blend with the park’s natural scenery, providing sanctuary for herpetofauna (reptiles and amphibians) and creating spaces for wetland plants to thrive. Additionally, recycled rockfill materials from the fill bank at Tseung Kwan O Area 137 are utilized for the unexposed gabion area. The thoughtful design considerations for the channel ensure minimal impact on small wildlife. The project also includes structures like decks and ramps within the channels, facilitating safe animal passage without getting trapped.

Supporting local agriculture, the park offers pump pits and electricity supply along the waterways, favoring eco-friendly electric pumps over traditional diesel generators that could be noisy and non-environmental friendly.

As the LVNP nears completion, its expanded wetlands have become an attractive spot for many bird species to forage, rest and breed. Our works to enhance LVNP’s high-value ecosystems have rejuvenated its wetlands, creating a better habitat that continues to draw an increasing variety of birds to this bird paradise.