Shijiu Lake Dike

Overview

Shijiu Lake Dike is the lake dike on the Lishui reach of Shijiu Lake. Shijiu Lake lies in the south of Lishui District, a boundary lake between Lishui, Gaochun and Dangtu in Anhui, a through-flow, throughput-type and seasonal lake whose water enters and leaves by the Yunliang River and the Guxi River (Lishui District Water Affairs Bureau, 24 June 2024).

Length: the Lishui District Water Affairs Bureau's reply of 2025 records that "the polder embankment within Lishui District is about 30.42 km long, protecting the lives, property and important facilities of the people along the lake". This entry takes 30.42 km for its length field. The design figures in the 2014 environmental impact report are 30.42 km of lake dike and 4.31 km of port dike reinforced in the Lishui reach, 34.73 km of dike in all; that document is a 2014 design document, not a completion document.

The basin is Shijiu Lake.

Three towns and subdistricts are involved: Honglan Subdistrict, Hefeng Town and Jingqiao Town. The official sources do not name the towns and subdistricts of the dike reach by reach, and this entry fills them in by the townships along Shijiu Lake within Lishui: the Jiangsu Provincial Department of Natural Resources' notice of confirmed registration of January 2026 records that the registered unit of Shijiu Lake borders Honglan Subdistrict to the north and Hefeng Town to the east, and the district government's Jingqiao Town page records that Jingqiao Town faces Shijiu Lake on its west; the reach names listed in the 2014 environmental impact report include Luoshan Village, which belongs to Hefeng Town (district government administrative divisions page).

Management: Shijiu Lake and the water works connected with it are under the Jiangsu Provincial Department of Water Resources, with day-to-day management by the Qinhuai River Management Office and local responsibility resting with Lishui and Gaochun districts; the provincial department has commissioned the Nanjing Hydraulic Research Institute to carry out a safety appraisal of the Shijiu Lake dike once every five years (Lishui District Water Affairs Bureau, 22 October 2025). The Measures for the Management and Protection of Water Conservancy Works in Lishui District give the management area of Shijiu Lake as 40 m beyond the toe of the dike, bounded by the parallel dike river where there is one, 12 m beyond the water-side edge of the road where a road replaces the dike, and the reservoir area below 12.50 m on the Wusong datum where there is no dike; Article 19 of the same measures lists the Shijiu Lake dike among the works whose maintenance costs the district finance bureau enters in its budget.

Formation and change

Approval: in October 2015 the Provincial Development and Reform Commission approved the Shijiu Lake Dike Flood Defence Capacity Improvement Project under Su Fa Gai Nong Jing Fa [2015] No. 1182, at an approved project investment of 472 million yuan (Lishui District Water Affairs Bureau, 24 June 2024); the same bureau's reply of 2025 writes the same figure as an approved estimated investment of 472 million yuan. The wording differs; the figure agrees.

Works, 2015 to 2017: 32.58 km of dike strengthened or newly built; 4.125 km of water-side slope newly protected, 25.105 km strengthened and 4.125 km rebuilt; 39.43 km of flood-control road on the dike crest newly built; ponds filled behind the dike and shelter belts planted (Lishui District Water Affairs Bureau, 22 October 2025). The 32.58 km is the length of works, new build included, and is not the same measure as the 30.42 km of polder embankment within the district.

Design figures, 2014 environmental impact report, submission version: 30.42 km of lake dike and 4.31 km of port dike reinforced in the Lishui reach, 34.73 km of dike in all, 85 structures, a 40-year flood standard, a grade 3 dike, a design flood level of 12.50 m, a crest level of 14.50 m and a rear berm at 11.00 m, at a total project cost of 639.7583 million yuan; the reach is divided into nine sections, named in order the Tuanjie Polder reach, Huaxigang to Longkan River, Longkan River to Tianshengqiao River, Tianshengqiao River to Xinqiao River, Xinqiao River to the north flood-diversion ditch of Lianhe Polder, that ditch to the Luoshan flood-diversion ditch, the Luoshan ditch to Huangjia River, Huangjia River to Dongshan River, and Zhangjia River to Ousiyan. The same report gives the whole project, Shijiu Lake and Gucheng Lake together, as 80.05 km of lake dike and 6.41 km of port dike reinforced, 86.46 km in all, 117 structures, a total project cost of 1,310.781 million yuan and a construction period of 33 months; the task of the works is to protect 214 sq km of polder around the lake.

Completion and acceptance: the works have a 40-year flood standard and a grade 3 dike; they were completed in early November 2017 (Lishui District Water Affairs Bureau, 22 October 2025) and passed completion acceptance in December 2019 (Lishui District Water Affairs Bureau, 24 June 2024). Completion and acceptance are two events and are not to be merged.

An earlier round: the Eleventh Five-Year water plan records that during the Tenth Five-Year period 24.67 km of the Shijiu Lake dike was brought up to standard (People's Government of Lishui County, Lu Zheng Fa [2005] No. 76); that project and the flood defence capacity improvement project approved in 2015 are not the same project and must not be added together. The 2014 environmental impact report recalls that Nanjing reinforced the lake dike between 1999 and 2002, to a flood standard of about 20 to 40 years. The 14th Five-Year Water Development Plan lists "carrying out the Shijiu Lake Dike Flood Defence Capacity Improvement Project in the Lishui reach, raising the flood standard of the Lishui reach of the Shijiu Lake dike to 40 years" among the achievements of the 13th Five-Year period (Lu Zheng Ban Fa [2021] No. 87).

Emergency works in 2025: in 2025 emergency works were carried out on the Shijiu Lake dike against seepage in parts of the dike, damaged crest roads and water-side slope scour, at a total investment of about 12 million yuan, and the works are complete (Lishui District Water Affairs Bureau, 22 October 2025).

Landscape and visiting

Belt of scenery around the lake: the Lishui District Water Affairs Bureau's reply of 2025 records that planting behind the dike, a viewing platform on the water side, an overhang on the landward slope, footpaths and pocket parks have begun to form a belt of scenery around the lake; the protection and management area of Shijiu Lake includes the Shijiu Lake bridge. In October 2015 the Shijiu Lake bridge, 12,617.2 m long, opened to traffic (Nanjing Municipal Water Bureau, 24 October 2025).

Design crest and corridor: the 2014 environmental impact report records that ponds within 20 m behind the dike were filled in, 106 ponds in the project area in all; a shelter-belt ecological corridor 20 m wide was set beyond the toe of the landward slope; and the flood-control road on the crest is 8 m wide in urban reaches and 6 m wide, asphalt, outside them. This group of figures is the 2014 design basis.

Visiting information: the Shijiu Lake dike is a flood defence work, and this site has found no first-tier source for tickets, opening times and visitor services on the dike itself; the opening of the viewing platforms, footpaths and pocket parks along the lake changes from season to season, and this site does not fix figures. Before travelling, readers should go to the official notices of the district water department, the district culture and tourism department and the local townships. This entry was checked to September 2026.

Open questions

• Three figures for the length: about 30.42 km of polder embankment within the district (Lishui District Water Affairs Bureau, 22 October 2025, the value used here); 32.58 km of dike strengthened or newly built (the 2015-2017 works, new build included); and the 2014 environmental design figures of 30.42 km of lake dike with 4.31 km of port dike, 34.73 km in all. The three are different measures and must not be added together or used one for another.
• The 30.42 km of lake dike reinforced in the Lishui reach, a 2014 design figure, and the about 30.42 km of polder embankment, the 2025 reply's total dike length, are the same number but one is a design length of reinforcement and the other a total dike length, and the two must not on that account be asserted to be identical.
• Investment: both replies give 472 million yuan, one as an approved project investment and one as an approved estimated investment; the 2014 environmental design figures are 639.7583 million yuan for the Lishui reach and 1,310.781 million yuan for the whole project. The design basis and the approval basis are shown side by side, not converted and not averaged.
• Area gap: no official area is given for the Shijiu Lake dike itself, and this entry leaves the area field empty. The "214 sq km of polder" in the 2014 environmental impact report is the protected area of the whole project, Shijiu Lake and Gucheng Lake together, not the polder area of Lishui District, and must not be used interchangeably with the "293.52 sq km of low-lying polder along rivers and lakes" in the Eleventh Five-Year water plan.
• Completion and acceptance are set apart: completed in November 2017 and passing completion acceptance in December 2019 are two events and are not to be merged into one year.
• The towns and subdistricts are not confirmed reach by reach: no official source names the towns and subdistricts of the Shijiu Lake dike reach by reach, and this entry fills them in by the townships along Shijiu Lake, from the registered boundaries and the district government's town page; that is not the same as the list of townships in the return of fishing grounds to the lake, Honglan, Shiqiu, Hefeng, Baima and Jingqiao.
• Internal inconsistency in the 2014 environmental impact report: table 2.3-1 gives 80.05 km of lake dike reinforced, while table 2.5-1 gives 76.56 km reinforced plus 2.49 km newly built, 79.05 km in all, and the report does not explain the difference; this site draws no conclusion from either figure.
• Two names: the management system uses "the Shijiu Lake dike" and the project name uses "Shijiu Lake Dike"; the two refer to the same lake dike, and this site repeats them as they stand without distinguishing them further.