Original Article：https://mp.weixin.qq.com/s/cjsgvmVlnyi8A7sRmiVB9g
Research and Practice of Lake Ecological Restoration
Lake Ecological Restoration Technologies: Standards & Specifications, Technical Pathways and Successful Cases
As critical components of the Earth’s ecosystem, lakes perform vital functions including climate regulation, water conservation, and biodiversity protection. Nevertheless, accelerated urbanization, industrial-agricultural development and climate change have posed unprecedented threats to lake ecosystems worldwide, manifested as water eutrophication, biodiversity loss and altered hydrological regimes. Lake ecological restoration has become a core priority of global ecological governance, with its technical system and practical approaches continuously maturing. This paper systematically reviews relevant standards, technical frameworks and typical cases of lake ecological restoration, offering references for lake protection and governance.
I. Standard and Specification System for Lake Ecological Restoration
1. National-level Standards
China has initially established a national standard system for lake ecological restoration covering the following dimensions:
Technical Guidelines for Aquatic Ecosystem Health Assessment (GB/T 43476-2023), implemented in April 2024, incorporates indicators such as the ecological flow satisfaction index and soil-water conservation rate for the first time, shifting assessment focus from standalone water-quality targets toward overall aquatic ecosystem health.
Code for River-Lake Health Assessment (SL/T 793-2025), effective March 2026, classifies rivers and lakes into four health status categories and proposes differentiated restoration strategies, providing technical support for scientific river-lake health evaluation.
Guidelines for Happy River-Lake Assessment — Part 1: Rivers with Catchment Area ≤ 3 000 km², to take effect on 1 May 2026, translates the abstract concept of “happiness” into quantifiable metrics across five dimensions: safety, health, beauty, culture and development, delivering a fresh assessment framework for lake restoration.
2. Local Standards
Provinces have formulated region-specific local standards tailored to local lake conditions:
Hubei Province: Technical Specification for Aquatic Vegetation Restoration of Degraded Urban Lakes (DB42/T 2477-2025), implemented in February 2026, fills technical gaps in restoring aquatic plants in degraded urban lakes and specifies full-process technical requirements for investigation-evaluation, restoration modes and implementation procedures.
Hunan Province: Technical Specification for Lake Ecological Restoration and Governance (T/HSES 0005-2025), released in May 2025, defines technical requirements covering basic principles, investigation-evaluation, systematic governance, effect assessment and operation-maintenance for natural and man-made lakes (including reservoirs).
Jiangsu Province: Local standards including Specification for Lake Aquatic-Ecological Monitoring (DB32/T 3202-2017) and Code of Practice for River-Lake Ecological Dredging Construction (DB32/T 3258-2017) supply technical foundations for monitoring and engineering implementation of lake restoration.
Anhui Province: Technical Regulation for Forest-Grass Ecological Restoration around Chaohu Lake (DB34/T 4890-2024), enforced August 2024, sets out systematic requirements for ecological surveys, engineering design and technical measures targeting riparian-littoral zone restoration around Chaohu Lake.
Zhejiang Province: Trial Technical Guidelines for River-Lake Ecological Protection and Restoration (Zhejiang Province, 2024) innovatively puts forward a five-dimensional spatial goal: safe flood-discharge space, pulsing water-volume space, sound water-quality space, diversified habitat space and harmonious water-access space, bringing new ideas to lake restoration.
Guangdong Province: Guidelines for River-Lake Health Status Investigation and Indicator Calculation (DB44/T 2800-2025), issued in 2025, specifies special technical indicators for halophyte screening and salt-dust prevention with regard to salt-water lakes.
II. Technical System and Key Links of Lake Ecological Restoration
1. Pollution Control Technologies
Pollution control serves as the primary step for lake ecological restoration and consists of external pollution source control and internal pollution remediation.
External source control: Reduce pollutant inflows via wastewater treatment plant upgrading, pipe-network reconstruction, interception ditches for agricultural non-point pollution, and ecological revetments. For instance, the Chaohu Basin adopts targeted “one-river-one-policy” management to implement differentiated governance for 15 major lake-feeding rivers.
Internal source control: - Sediment elution technology: Physically separate pollutants followed by secondary flocculation to precisely remove organic contaminants while preserving inorganic substrate, cutting sludge volume. Applied in West Lake of Fuzhou, this technology reduced sludge output by 90 % and lowered costs by 30-50 %. - In-situ capping: Cover contaminated bottom sediment with gravel or river sand to restrain nitrogen and phosphorus release. - Enhanced microbial remediation: Select bacterial strains such as nitrifying bacteria and polyphosphate-accumulating bacteria, combined with pre-aeration, to boost natural water self-purification capacity. - Phosphorus inactivation technology: The ROLAND PLOCHER Integral-Technik from Germany catalyzes biochemical reactions through information-loading devices to mitigate phosphorus release from bottom sediment.
2. Ecological Reconstruction Technologies
As the core component of lake restoration, ecological reconstruction includes hydrological regulation, habitat rehabilitation and biodiversity recovery.
Hydrological regulation technologies: - Model simulation: The MIKE21 two-dimensional hydrodynamic-water quality coupled model was deployed in Xinghai Lake to optimize ecological water-replenishment schemes. - Precise regulation: Gate-dam operations simulate natural hydrological rhythms. Poyang Lake adopts the “low-connectivity-high-carbon-sequestration” strategy to delay inundation in flood-rising phases and optimize connectivity during water recession for enhanced carbon-sink performance. - Ecological water-level control: Hulun Lake applies the “stabilize volume, prioritize quality” strategy, maintaining reasonable water levels through water-resource allocation projects.
Habitat rehabilitation technologies: - Littoral-zone and buffer-zone restoration: Technical Guidelines for Littoral-zone and Buffer-zone Ecological Restoration Projects elaborates ecosystem functions, typology, problem diagnosis, restoration concepts and design schemes for lakeshore zones. - Ecological percolation islands: Wetlands around Chaohu Lake repurpose fish-pond sediment on-site. Engineering piles stabilize sediment beneath artificial islands, where metasequoia and Chinese tallow trees are planted, forming integrated systems combining hydraulic engineering and ecological restoration. - Submerged macrophyte restoration: At Dabokou in Caohai (Dianchi Lake), sediment clearance, ecological buffer-belt construction and higher-plant community transformation shift the water regime from algae-dominated turbid state toward macrophyte-dominated clear-water state.
Biodiversity recovery technologies: - Fish stock enhancement: Hulun Lake carries out conservation and population-recovery projects for native fish species such as Amur pike and Pseudaspius leptocephalus. Trophic-cascade effects suppress small-sized Hemiculter bleekeri and indirectly raise zooplankton biomass. - Bird habitat creation: Wetland restoration for Chaohu Lake retains 10 % of paddy fields as food sources for migratory birds, flooded to a depth of 30-50 cm to secure roosting and foraging grounds. - Biomanipulation: In Taihu Lake, predatory fish including mandarin fish and culter are stocked to control small wild fish populations, while freshwater mussels (Cristaria plicata) mitigate snail hazards, building complete food-web structures.
3. Long-term Management Technologies
Long-term management underpins lake restoration, covering monitoring-early-warning and eco-product value realization.
Monitoring and early-warning technologies: - AI-enabled intelligent monitoring: “Little Color Cloud”, an eco-environment AI assistant in Kunming, leverages artificial intelligence for algal-bloom early warning and dynamic biodiversity assessment, generating more than 520 000 environmental alert records. - Automatic water-quality stations: Hulun Lake operates a three-dimensional research-monitoring network covering water environments, sediments and basin ecosystems, with 42 monitoring towers, six automatic water-quality stations and three automatic air-quality stations for real-time tracking of water levels, water quality and grassland conditions.
Eco-product value realization technologies: - Carbon-sink development: Hydrological regulation boosts carbon sequestration in Poyang Lake wetlands. Wetland vegetation carbon stock grew at an annual rate of 0.09 Tg between 2000 and 2020. - Eco-tourism: The 129-km lakeshore buffer belt of Erhai Lake links more than 100 Bai ethnic villages along its route, with its ecological corridor receiving 23 million tourist visits annually. Xiaohekou Scenic Area of Hulun Lake, hosting 750 000 visitors per year, is advancing toward national 5A-class scenic-area status. - Eco-product processing: Inner Mongolia Jiajia New Materials Co., Ltd. collects roughly 60 000 tons of reeds from Wuliangsuhai Lake each year to manufacture environmentally friendly building materials, achieving an output value of 170 million RMB in 2024.
III. Typical Cases of Lake Ecological Restoration
1. Ecological Restoration of “One Lake and Two Wetlands” in Inner Mongolia
Hulun Lake: Guided by the overall layout of “one lake, three zones, four belts”, governance implements four major categories of measures: pollution interception, ecological restoration, industrial transformation and scientific monitoring. Its water-surface area expanded from 1 759 km² before treatment to 2 241.9 km² in 2026. Total fish biomass has increased from less than 90 000 tons to over 150 000 tons. Bird species rose from 333 in 2013 to 346 in 2025, with population size growing from 39 000 to 168 000 individuals.
Wuliangsuhai Lake: Transformed from a “soy-sauce-colored lake” back to a “Pearl beyond the Great Wall”. Annual ecological water diversion of 500 million m³ from the Yellow River, wastewater-treatment plant construction and ecological revetment works lifted water quality from inferior Grade-V to stable Grade-V, with local sections better than Grade-V. Its water-surface area stabilizes at 293 km² with maximum water depth of around 4 m, supporting 29 fish species and 264 bird species.
Daihai Lake: Revived from drying-up risk to thriving aquatic life. The “three-water coordinated governance” strategy covers water-resource protection, water-environment improvement and aquatic-ecological restoration. Water-surface area reaches 64.06 km², water level 1 216.97 m and water storage capacity 340.1 million m³ — all hitting decade-long highs.
2. Ecological Restoration of Dianchi Lake in Yunnan Province
The Dianchi Lake basin has carried out “Seven Major Initiatives” (illegal construction rectification in basins, rural domestic-waste-water-solid-waste treatment, agricultural non-point-source pollution reduction, water-saving and ecological restoration, accelerated pollution-interception projects, comprehensive law-enforcement supervision and public protection advocacy for Erhai Lake) and “Eight Major Offensives” (lakeside pollution interception, ecological resettlement, mine remediation, agricultural non-point-source pollution control, river-course regulation, lakeside ecological restoration, water-quality upgrading and excessive-development governance). Consequently, Erhai Lake maintains consistently good water quality, reaching Grade-II in Q1 2026. At Dabokou of Caohai, 148 900 m² of submerged vegetation was restored together with stocking of 2 600 mandarin fish and 2 600 topmouth culter. Total phosphorus dropped below 0.06 mg/L, water transparency improved to 1 m, and cyanobacterial blooms were avoided.
3. International Lake-Restoration Cases
The Great Lakes (United States): Under the Great Lakes Restoration Initiative (GLRI), over USD 4.1 billion was invested into more than 8 100 projects including wetland rehabilitation and invasive-species (e.g. zebra mussel) control. High-level Inter-Agency Task Forces (IATF) and Regional Working Groups (RWG) were established to secure accountability and effective decision-making.
Lake Geneva (Switzerland): More than 200 wastewater-treatment plants were built, alongside mobile ecological-dredging platforms known as “mobile water-treatment fortresses”, restoring lake water quality to drinking-water standards. Volunteer-driven large-scale clean-up campaigns (the 11th major lake clean-up since 2005 removed 128 000 kg of litter) and round-the-clock technical monitoring sustain restoration outcomes.
Lake Como (Italy): 3D-printed biodegradable substrates were deployed to optimize growing conditions for Hydrilla verticillata (25-27 ℃, 6-h-light/6-h-dark photoperiod). Plant density multiplied 57 times within four months and filamentous algae were suppressed, validating Hydrilla verticillata as a feasible option for habitat restoration in coastal lakes.
IV. Major Challenges Facing Lake Ecological Restoration
1. Financial and Cost-related Challenges
Heavy reliance on fiscal investment: Initial investment for lake-restoration projects ranges from 50 million to 200 million RMB. Operation-maintenance cycles last 10-20 years, with annual maintenance costs accounting for 5-15 % of initial capital outlay. Annual central-government ecological-compensation funds exceed 200 billion RMB, yet local fiscal pressure remains substantial, as key ecological zones largely overlap with under-developed regions.
Under-developed market-oriented mechanisms: Realization mechanisms for eco-product value remain imperfect. For example, the first eco-product transaction for a reservoir-type water-scenic-area in Ezhou closed at merely 2.2228 million RMB, far below its assessed value of 402 million RMB. Market-based compensation channels such as eco-tourism and carbon-credit trading are not fully operational.
2. Technical Bottlenecks and Limitations
Difficulty in phosphorus reduction: Nanobubble technology shows limited total-phosphorus removal efficiency in Taihu Lake, calling for combined sediment treatment and biomanipulation. Neglect of hydrological fluctuations caused repeated collapse of submerged-plant communities in Lake Tämnaren (Sweden), resulting in failed restoration despite million-euro investment.
Insufficient biological-invasion prevention: Quagga-mussel invasion in Switzerland drove restoration-cost surges equivalent to roughly 480 million EUR, exposing deficiencies in biological-risk prevention and lagging monitoring capacity.
Poor technology adaptability: The fractal watershed model precisely identified 85 % of non-point-source pollution entry points for Lake Veluwemeer (Netherlands), outperforming conventional approaches.
3. Governance and Coordination Difficulties
Cross-jurisdictional barriers: Monitoring-data sharing across provincial boundaries is hampered within the Yangtze River Basin. Compensation agreements for the Yellow River Basin generate disputes without scientifically accounting for pollutant weights and opportunity-cost disparities, highlighting demand for improved accounting frameworks.
Rigid policy implementation: Some regions adopt blanket development bans, preventing eco-product value creation. Positive-list access rules for general-control zones within nature reserves are needed to strike a balance between conservation and development.
Deficient long-term mechanisms: Lake Długoze relied on artificial aeration from 1987-2000 with limited outcomes; only after phosphorus-inactivation agent PAX18 was applied did the system shift from saprophytic to clear-water status. This demonstrates that single technical measures cannot sustain long-term restoration success.
V. Future Development Trends of Lake Ecological Restoration
1. Policy and Institutional Innovation
Systematized ecological-compensation mechanisms: Implementation Plan for Advancing Comprehensive Ecological Compensation transforms compensation logic from simple fiscal transfer toward systematic governance, constructing an integrated system combining vertical fiscal transfers, horizontal inter-regional compensation and market-based instruments. By 2030, comprehensive ecological-compensation frameworks will be further refined to improve benefits for ecological protectors.
Value realization of ecological products: Financial tools such as ecological-compensation funds will be explored to support sustainable development. Water-conservancy asset-backed securities (ABS) projects in Ezhou expand financing channels, forming a tiered promotion pattern with national-level leadership, provincial-level demonstration and municipal-level implementation.
2. Technology Integration and Innovation
AI-empowered monitoring platforms: Kunming’s “Little Color Cloud” integrates remote sensing and Internet-of-Things technologies for algal-bloom early warning and dynamic biodiversity assessment, with AI recognition accuracy exceeding 85 %.
Gene-editing-assisted applications: Salt-tolerant plants (Sunshan Wetland example) and cyanobacteria-resistant microbial strains will be screened to enhance site-specific adaptability of restoration techniques.
Modernization of traditional techniques: For Huohua Lake in Jiuzhaigou, an internationally-recognized calcium-tufa-ecosystem restoration solution was adopted, combining vibro-crushed-stone foundation stabilization, glutinous-rice-mortar dykes, bamboo-anchored reinforced slope protection, eco-material joint sealing, fractal-based landscape design and native-species revegetation.
3. Synergistic Development of Ecology and Economy
Eco-tourism: The Erhai Lake ecological corridor receives 23 million annual visits, creating over 800 local jobs. Average tourist length-of-stay rose from 1.76 days to 3.21 days.
Circular agriculture: The “rice-duck” integrated aquaculture system is promoted around Lake Victoria. Ducks suppress pests and weeds to cut pesticide use; biogas digestion and photovoltaic panels supply household clean energy, reconciling ecological and economic benefits.
Eco-product processing: Reeds harvested from Wuliangsuhai Lake are processed into eco-friendly building materials, yielding 170 million RMB output value in 2024 and delivering both ecological and economic gains.
VI. Conclusions and Recommendations
Lake ecological restoration constitutes a systematic project that should adhere to core principles: respect natural laws, prioritize pollution abatement, pursue holistic watershed governance and build enduring operational mechanisms. Current lake-restoration practice has evolved from single-dimensional water-quality improvement toward holistic aquatic-ecosystem health, and from localized treatment to full-basin integrated governance.
Countermeasures addressing existing challenges are proposed as follows:
- Improve financing security: Accelerate diversified fundraising and encourage participation from enterprises and non-profit organizations. Draw lessons from Ezhou’s ecological-compensation-trading mechanism and explore market trading instruments for carbon sinks, water rights and pollutant-emission permits. - Strengthen research on technology adaptability: Classify lakes under the “state-rate” analytical framework. For instance, Type-III lakes require breaking detrimental positive-feedback loops, whereas Type-IV lakes must accommodate new stable states, with restoration pathways tailored accordingly. - Perfect cross-regional coordination: Learn from the IATF mechanism under the United-States GLRI program to establish high-level inter-departmental working groups with clear division of responsibilities. Hulunbuir’s institutional reform consolidated multiple lake-management agencies so that “one matter is managed by one competent department”. - Advance eco-product value realization: Foster a development pattern where conservation enables sustainable utilization and utilization feeds back into conservation. The “aquatic-grass plus” model in Liangzi Lake generates 5 400 tons of annual eco-agricultural output and increases incomes for 158 farming households by 10.8 million RMB.
Future lake ecological restoration will emphasize institutional coordination alongside technological innovation. A collaborative transformation model linking research institutes and local authorities will embed remote-sensing inversion, model simulation and mechanistic analysis into platform development for precision governance. Restoration efforts must shift from symptom-targeted partial interventions to holistic ecosystem rehabilitation, and from lake-isolated management toward whole-basin collaborative governance, so as to achieve lasting healthy development of lakes.
