Ergan River

Overview

The Ergan River is a main watercourse of the Qinhuai system and a tributary of the Lishui River (Dongping Subdistrict environmental impact report, January 2020). The district government's geographical position page lists the Ergan River in the Qinhuai system alongside the Lishui, Yigan and Sangan rivers, and gives its length as 25.60 km.

There are two accounts of its two ends. The Dongping Subdistrict environmental report gives "a tributary of the Lishui River, 25.60 km long, running west by north, starting at Dongping and crossing Dongping, Qunli and Wushan to Zhetang before reaching Wusha Bridge and flowing into the Qinhuai"; the environmental impact report for the Ergan River desilting project gives "the Ergan River runs from Fangbian Reservoir to the Lishui River, 26.0 km in all". The first puts the end at Wusha Bridge on the Qinhuai, the second at the Lishui River, and the two stand side by side without a choice being made.

Three figures for the length: 25.60 km (district government geographical position page; Dongping Subdistrict environmental report), 26.0 km (environmental impact report for the Ergan River desilting project, December 2019) and 26.36 km (Master Plan for the Wuxiang Mountain National Forest Park, 2023-2035). This entry's length takes 25.60 km.

Two figures for the basin: the Eleventh Five-Year water plan and the Wuxiang Mountain forest park plan give a catchment of 227.10 sq km; the desilting project report gives a basin area of 254 sq km. Neither source says whether basin area and catchment mean the same thing, and this site does not treat them as equal.

The subdistricts are Dongping and Zhetang: the Dongping Subdistrict report describes the river as crossing Dongping, Qunli and Wushan to Zhetang, in which Qunli and Wushan are former township names and are now both communities of Zhetang Subdistrict; the 2018 annual implementation scheme for water pollution prevention records the assessment unit for the Kaitai Bridge cross-section on the Ergan River as Dongping Town, now Dongping Subdistrict.

Upstream reservoir: the Ergan River rises below Fangbian Reservoir, also called Dongping Reservoir and Dongping Lake, with a catchment of 77.1 sq km and a total capacity of 50.7 million cubic metres, the largest medium-sized reservoir in Lishui District and the second largest in Nanjing (Dongping Subdistrict environmental report, December 2019).

Formation and change

The Ergan River is one of the district's seven main watercourses (Measures for the Management and Protection of Water Conservancy Works in Lishui District, Lu Zheng Gui [2022] No. 2).

Channel improvement: the desilting project report records a desilting reach from Heshang Bridge to 500 m below Kaitai Bridge, at chainage K3+900 to K14+650, 10.75 km long, with 372,700 cubic metres of silt removed; the project cost 39.53 million yuan and ran from January to December 2020. The report also records that the river falls under different administrations, making improvement along its course difficult, that four rounds of improvement have already been carried out, and that no desilting had been included in any of them.

Drainage works: the new Zhangxi Polder drainage pumping station stands behind the left bank of the Ergan River at chainage 18+400, with a design flow of 10 cubic metres per second (Jiangsu Provincial Development and Reform Commission and Jiangsu Provincial Department of Water Resources, Su Fa Gai Nong Jing Fa [2019] No. 667). The same document records that the Sanya, Zhangxi and Lingzhuang polders lie within the Lishui Economic Development Zone and drain into the Ergan and Yigan rivers respectively.

Flood defence: the Ecological Rivers and Lakes Action Plan (2019-2020) sets a target of 20- to 50-year flood defence for the Yigan and Ergan rivers in the Qinhuai basin (Lu Zheng Ban Fa [2019] No. 92).

No first-tier source has been found for when the Ergan River was cut or for its final alignment, so nothing is written here.

Landscape and visiting

Ecological corridor: the pre-approval public notice of the Territorial Spatial Ecological Protection and Restoration Plan of Lishui District (2021-2035) lists the Ergan River among the waterway corridors of its multiple-corridor pattern (pre-approval notice, July 2026, not an instrument in force).

Water quality cross-section: Kaitai Bridge on the Ergan River is a provincial-level assessment cross-section (Lishui Ecological Environment Bureau, published on the district government website in January 2022). The table gives the name and level of the cross-section only, not a water quality class.

No first-tier source has been found for footpaths, waterside platforms, viewing facilities or opening information along the Ergan River, so no visiting detail is given; readers who need it should go to the official notices of the district water department, the district culture and tourism department and the local subdistricts. Information is current to September 2026.

Open questions

• Three figures for the length: 25.60 km (district government geographical position page and Dongping Subdistrict environmental report, the value used here), 26.0 km (desilting project report, December 2019) and 26.36 km (Master Plan for the Wuxiang Mountain National Forest Park, 2023-2035). All three are shown and none is chosen.
• Two accounts of the two ends: the Dongping Subdistrict report has the river starting at Dongping and reaching Wusha Bridge on the Qinhuai; the desilting project report has it running from Fangbian Reservoir to the Lishui River. Both are shown and neither is merged into the other.
• Two figures for the basin: 254 sq km (desilting project report) and a catchment of 227.10 sq km (Eleventh Five-Year water plan; Wuxiang Mountain forest park plan). Whether the two mean the same is not stated, and they are not treated as equal.
• Wusha Bridge is uncertain: the Dongping Subdistrict report puts it where the Ergan River enters the Qinhuai, while Wusha Bridge is also the name of a provincial-level cross-section on the Lishui River; the source does not say whether the bridge is on the Ergan, on the Lishui, or at their meeting, and the wording is repeated as it stands.
• The fishing-ban list: Lu Zheng Fa [2020] No. 75 lists the Ergan River among the rivers connected with Shijiu Lake where fishing is banned all year, which stands alongside the district government's geographical position page placing the Ergan River in the Qinhuai system; both are recorded here without explanation.
• Two counts of main watercourses: the district government's geographical position page and the Measures for the Management and Protection of Water Conservancy Works give seven; the pre-approval notice of the territorial spatial plan gives eight. They are shown side by side and neither is chosen.
• The upstream reservoir has three names, Fangbian Reservoir, Dongping Reservoir and Dongping Lake, all for the same water; this entry uses Fangbian Reservoir and explains the other two.