八里灣閘改建工程為2級(jí)建筑物,老湖設(shè)計(jì)防洪水位44.79m,相應(yīng)新湖水位36.79m。該閘為鋼筋砼樁基開敞式水閘,設(shè)計(jì)南排泄洪流量450m3/s,相應(yīng)老湖水位42.99m;設(shè)計(jì)灌溉引水流量25m3/s,相應(yīng)設(shè)計(jì)引水位39.59m;設(shè)計(jì)排澇流量18.82m3/s,提水站出水池設(shè)計(jì)水位42.09m,相應(yīng)老湖水位41.79m。全閘共設(shè)7孔,1低6高,孔口凈寬8m,底板高程為37.79m(低孔)、40.29m(高孔),采用胸墻式孔口布置。6個(gè)高孔孔口尺寸寬×高=8×3.5低孔孔口尺寸寬×高=8×3m,閘孔總凈寬56m。